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  • 1.
    Abdalla, Hana
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Diab, Asim
    Department of Neurology, University of Texas Southwestern Medical Center, Dallas, USA.
    Forslund, Tony
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Bakhiet, Moiz
    Department of Medicine, Divisions of lnfectious Diseases, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden.
    Stendahl, Olle
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Expression of inducible nitric oxide synthases and nitrotyrosine during the course of Haemophilus influenzae type b meningitis in ratManuscript (preprint) (Other academic)
    Abstract [en]

    Bacterial meningitis continues to be a major health problem and despite great advances in antimicrobial therapy the fatality rate remains high. There is increasing evidence that leukocyte-endothelial interactions are involved in CNS damage during bacterial meningitis. Once leukocytes have entered the CSF they cause injury by releasing toxic molecules such as nitric oxide (NO) and reactive oxygen species (ROS). The induction of iNOS was examined by assessing intracerebral mRNA expression and protein production during the course of Haemophilus influenzae type b (Hib) meningitis in the rat. Induction of iNOS mRNA was detected 12h postinoculation (pi), followed by a gradual reduction. The increased number of intracerebral iN OS expressing cells was detected at 12h pi. followed by further elevation to peak expression at 72h pi. The iNOS positive tissue also bound antibodies specific for nitrotyrosine. The expression of iNOS and NO production, as shown by nitrotyrosine expression, correlated with disease severity, suggesting that activation of iNOS may play an important role in Haemophilus irifluenzae type b meningitis.

  • 2.
    Abdalla, Hana
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Schön, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Effects of CNI-1493 on human granulocyte functions2006In: Immunobiology, ISSN 0171-2985, E-ISSN 1878-3279, Vol. 211, no 3, p. 191-197Article in journal (Refereed)
    Abstract [en]

    During acute bacterial infections such as sepsis and meningitis, activation of inflammatory mediators such as nitric oxide (NO) plays a crucial role in both pathogenesis and host defense. We have previously reported that CNI-1493, a macrophage deactivator, reduced mortality in infant rats infected with Haemophilus influenzae type b (Hib) with associated decrease in the number of granulocytes in the infected tissue. The aim of the present study was to investigate how CNI-1493 affects granulocytes and macrophages in vitro. Murine macrophages (RAW 264.7) pre-incubated with CNI-1493 prior to activation with lipopolysaccharide (LPS)/interferon gamma (IFNγ) had decreased NO production measured as NO2/NO3 levels and reduction in inducible NO-synthase (iNOS) expression. Reactive oxygen species (ROS) production was increased in formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated granulocytes following CNI-1493 treatment, whereas F-actin content, motility and chemotaxis were decreased under the same conditions. The effects of CNI-1493 on both NO production in LPS/IFNγ-activated macrophages and ROS production, F-actin content, motility and chemotaxis in granulocytes, may contribute to the reduced inflammatory response and increased survival in Hib-infected animals treated with CNI-1493.

  • 3.
    Abrahams, M
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Anaesthesiology. Östergötlands Läns Landsting, MKC - Medicin och kirurgicentrum, Anestesi.
    Sjöberg, Folke
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Plastic Surgery, Hand Surgery and Burns. Östergötlands Läns Landsting, Reconstruction Centre, Department of Plastic Surgery, Hand surgery UHL.
    Oscarsson, Anna
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Anaesthesiology. Östergötlands Läns Landsting, MKC - Medicin och kirurgicentrum, Anestesi.
    Sundqvist, Tommy
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology.
    The effects of human burn injury on urinary nitrate excretion. 1999In: Burns, ISSN 0305-4179, E-ISSN 1879-1409, Vol. 25, p. 29-33Article in journal (Refereed)
  • 4.
    Andersson, Henrik
    et al.
    Linköping University, Faculty of Medicine and Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Linköping. Linköping University, Department of Medical and Health Sciences, Division of Drug Research.
    Björnström-Karlsson, Karin
    Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Linköping. Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences.
    Eintrei, Christina
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Linköping.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Orexin A Phosphorylates the gamma-Aminobutyric Acid Type A Receptor beta(2) Subunit on a Serine Residue and Changes the Surface Expression of the Receptor in SH-SY5Y Cells Exposed to Propofol2015In: Journal of Neuroscience Research, ISSN 0360-4012, E-ISSN 1097-4547, Vol. 93, no 11, p. 1748-1755Article in journal (Refereed)
    Abstract [en]

    Propofol activates the gamma-aminobutyric acid type A receptor (GABA(A)R) and causes a reversible neurite retraction, leaving a thin, thread-like structure behind; it also reverses the transport of vesicles in rat cortical neurons. The awakening peptide orexin A (OA) inhibits this retraction via phospholipase D (PLD) and protein kinase CE (PKCE). The human SH-SY5Y cells express both GABA(A)Rs and orexin 1 and 2 receptors. These cells are used to examine the interaction between OA and the GABAAR. The effects of OA are studied with flow cytometry and immunoblotting. This study shows that OA stimulates phosphorylation on the serine residues of the GABA(A)R beta(2) subunit and that the phosphorylation is caused by the activation of PLD and PKCE. OA administration followed by propofol reduces the cell surface expression of the GABA(A)R, whereas propofol stimulation before OA increases the surface expression. The GABA(A)R beta(2) subunit is important for receptor recirculation, and the effect of OA on propofol-stimulated cells may be due to a disturbed recirculation of the GABA(A)R. (C) 2015 Wiley Periodicals, Inc.

  • 5.
    Björnsson, Bergthor
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Bojmar, Linda
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Olsson, Hans
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences.
    Sandström, Per
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Nitrite, a novel method to decrease ischemia/reperfusion injury in the rat liver2015In: World Journal of Gastroenterology, ISSN 1007-9327, E-ISSN 2219-2840, Vol. 21, no 6, p. 1775-1783Article in journal (Refereed)
    Abstract [en]

    AIM: To investigate whether nitrite administered prior to ischemia/reperfusion (I/R) reduces liver injury.

    METHODS: Thirty-six male Sprague-Dawley rats were randomized to 3 groups, including sham operated (n = 8), 45-min segmental ischemia of the left liver lobe (IR, n = 14) and ischemia/reperfusion (I/R) preceded by the administration of 480 nmol of nitrite (n = 14). Serum transaminases were measured after 4 h of reperfusion. Liver microdialysate (MD) was sampled in 30-min intervals and analyzed for glucose, lactate, pyruvate and glycerol as well as the total nitrite and nitrate (NOx). The NOx was measured in serum.

    RESULTS: Aspartate aminotransferase (AST) at the end of reperfusion was higher in the IR group than in the nitrite group (40 ± 6.8 μkat/L vs 22 ± 2.6 μkat/L, P = 0.022). Similarly, alanine aminotransferase (ALT) was also higher in the I/R group than in the nitrite group (34 ± 6 μkat vs 14 ± 1.5 μkat, P = 0.0045). The NOx in MD was significantly higher in the nitrite group than in the I/R group (10.1 ± 2.9 μM vs 3.2 ± 0.9 μM, P = 0.031) after the administration of nitrite. During ischemia, the levels decreased in both groups and then increased again during reperfusion. At the end of reperfusion, there was a tendency towards a higher NOx in the I/R group than in the nitrite group (11.6 ± 0.7 μM vs 9.2 ± 1.1 μM, P = 0.067). Lactate in MD was significantly higher in the IR group than in the nitrite group (3.37 ± 0.18 mM vs 2.8 ± 0.12 mM, P = 0.01) during ischemia and the first 30 min of reperfusion. During the same period, glycerol was also higher in the IRI group than in the nitrite group (464 ± 38 μM vs 367 ± 31 μM, P = 0.049). With respect to histology, there were more signs of tissue damage in the I/R group than in the nitrite group, and 29% of the animals in the I/R group exhibited necrosis compared with none in the nitrite group. Inducible nitric oxide synthase (iNOS) transcription increased between early ischemia (t = 15) and the end of reperfusion in both groups.

    CONCLUSION: Nitrite administered before liver ischemia in the rat liver reduces anaerobic metabolism and cell necrosis, which could be important in the clinical setting.

  • 6.
    Björnsson, Bergthor
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Winbladh, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Bojmar, Linda
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Gullstrand, Per
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Sandström, Per
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Conventional, but not remote ischemic preconditioning, reduces iNOS transcription in liver ischemia/reperfusion2014In: World Journal of Gastroenterology, ISSN 1007-9327, E-ISSN 2219-2840, Vol. 20, no 28, p. 9506-9512Article in journal (Refereed)
    Abstract [en]

    AIM: To study the effects of preconditioning on inducible nitric oxide synthase (iNOS) and interleukin 1 (IL-1) receptor transcription in rat liver ischemia/reperfusion injury (IRI). METHODS: Seventy-two male rats were randomized into 3 groups: the one-hour segmental ischemia (IRI, n = 24) group, the ischemic preconditioning (IPC, n = 24) group or the remote ischemic preconditioning (R-IPC, n = 24) group. The IPC and R-IPC were performed as 10 min of ischemia and 10 min of reperfusion. The iNOS and the IL-1 receptor mRNA in the liver tissue was analyzed with real time PCR. The total Nitrite and Nitrate (NOx) in continuously sampled microdialysate (MD) from the liver was analyzed. In addition, the NOx levels in the serum were analyzed. RESULTS: After 4 h of reperfusion, the iNOS mRNA was significantly higher in the R-IPC (Delta Ct: 3.44 +/- 0.57) group than in the IPC (Delta Ct: 5.86 +/- 0.82) group (P = 0.025). The IL-1 receptor transcription activity was reduced in the IPC group (Delta Ct: 1.88 +/- 0.53 to 4.81 +/- 0.21), but not in the R-IPC group, during reperfusion (P = 0.027). In the MD, a significant drop in the NOx levels was noted in the R-IPC group (12.3 +/- 2.2 to 4.7 +/- 1.2 mu mol/L) at the end of ischemia compared with the levels in early ischemia (P = 0.008). A similar trend was observed in the IPC group (11.8 +/- 2.1 to 6.4 +/- 1.5 mu mol/L), although this difference was not statistically significant. The levels of NOx rose quickly during reperfusion in both groups. CONCLUSION: IPC, but not R-IPC, reduces iNOS and IL-1 receptor transcription during early reperfusion, indicating a lower inflammatory reaction. NOx is consumed in the ischemic liver lobe.

  • 7.
    Björnsson, Bergthor
    et al.
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Winbladh, Anders
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Bojmar, Linda
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Trulsson, Lena
    Linköping University, Department of Clinical and Experimental Medicine, Surgery. Linköping University, Faculty of Health Sciences.
    Olsson, Hans
    Linköping University, Department of Clinical and Experimental Medicine, Molecular and Immunological Pathology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Diagnostics, Department of Clinical Pathology and Clinical Genetics.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Gullstrand, Per
    Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery UHL.
    Sandström, Per
    Linköping University, Department of Clinical and Experimental Medicine, Surgery. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Östergötland.
    Remote or Conventional Ischemic Preconditioning -Local Liver Metabolism in Rats Studied with Microdialysis2012In: Journal of Surgical Research, ISSN 0022-4804, E-ISSN 1095-8673, Vol. 176, no 1, p. 55-62Article in journal (Refereed)
    Abstract [en]

    Background. Ischemic preconditioning (IPC) of the liver decreases liver injury secondary to ischemia and reperfusion. An attractive alternative to IPC is remote ischemic preconditioning (R-IPC), but these two methods have not previously been compared. Material and Methods. Eighty-seven rats were randomized into four groups: sham operated (n = 15), 1 h segmental ischemia (IRI, n = 24), preceeded by IPC (n = 24), or R-IPC (n = 24) (to the left hindleg). IPC and R-IPC were performed with 10 min ischemia and 10 min of reperfusion. Analyses of liver microdialysate (MD), serum transaminase levels, and liver histology were made. Results. Rats treated with IPC and R-IPC had significantly lower AST, 71.5 (19.6) IU/L respective 96.6 (12.4) at 4 h reperfusion than those subjected to IRI alone, 155 (20.9), P = 0.0004 and P = 0.04 respectively. IPC also had lower ALT levels, 41.6 (11.3) IU/L than had IRI 107.4 (15.5), P = 0.003. The MD glycerol was significantly higher during ischemia in the R-IPC = 759 (84) mu M] and the IRI = 732 (67)] groups than in the IPC 514 (70) group, P = 0.022 and P = 0.046 respectively. The MD glucose after ischemia was lower in the IPC group 7.1 (1.2) than in the IRI group 12.7 (1.6), P = 0.005. Preconditioning to the liver caused an direct increase in lactate, glucose and glycerol in the ischemic segment compared with the control segment an effect not seen in the R-IPC and IRI groups. Conclusions. IPC affects glucose metabolism in the rat liver, observed with MD. IPC reduces liver cell injury during ischemic and reperfusion in rats. R-IPC performed over the same length of time as IPC does not have the same effect as the latter on ALT levels and MD glycerol; this may suggest that R-IPC does not offer the same protection as IPC in this setting of rat liver IRI.

  • 8.
    Björnström-Karlsson, Karin
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Linköping.
    Turina, Dean
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Health Sciences.
    Strid, Tobias
    Linköping University, Department of Clinical and Experimental Medicine, Division of Microbiology and Molecular Medicine. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Health Sciences.
    Eintrei, Christina
    Linköping University, Department of Medical and Health Sciences, Division of Drug Research. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Linköping.
    Orexin A Inhibits Propofol-Induced Neurite Retraction by a Phospholipase D/Protein Kinase C-epsilon-Dependent Mechanism in Neurons2014In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 9, no 5, p. e0097129-Article in journal (Refereed)
    Abstract [en]

    Background: The intravenous anaesthetic propofol retracts neurites and reverses the transport of vesicles in rat cortical neurons. Orexin A (OA) is an endogenous neuropeptide regulating wakefulness and may counterbalance anaesthesia. We aim to investigate if OA interacts with anaesthetics by inhibition of the propofol-induced neurite retraction. Methods: In primary cortical cell cultures from newborn rats brains, live cell light microscopy was used to measure neurite retraction after propofol (2 mu M) treatment with or without OA (10 nM) application. The intracellular signalling involved was tested using a protein kinase C (PKC) activator [phorbol 12-myristate 13-acetate (PMA)] and inhibitors of Rho-kinase (HA-1077), phospholipase D (PLD) [5-fluoro-2-indolyl des-chlorohalopemide (FIPI)], PKC (staurosporine), and a PKC epsilon translocation inhibitor peptide. Changes in PKC epsilon Ser(729) phosphorylation were detected with Western blot. Results: The neurite retraction induced by propofol is blocked by Rho-kinase and PMA. OA blocks neurite retraction induced by propofol, and this inhibitory effect could be prevented by FIPI, staurosporine and PKC epsilon translocation inhibitor peptide. OA increases via PLD and propofol decreases PKC epsilon Ser(729) phosphorylation, a crucial step in the activation of PKC epsilon. Conclusions: Rho-kinase is essential for propofol-induced neurite retraction in cortical neuronal cells. Activation of PKC inhibits neurite retraction caused by propofol. OA blocks propofol-induced neurite retraction by a PLD/PKC epsilon-mediated pathway, and PKC epsilon maybe the key enzyme where the wakefulness and anaesthesia signal pathways converge.

  • 9.
    Cedergren, Jan
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Rheumatology . Linköping University, Faculty of Health Sciences.
    Follin, Per
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medicine, Department of Infectious Diseases in Östergötland.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Lindmark, Maria
    Linköping University, Department of Medicine and Care. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Skogh, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Rheumatology . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre for Medicine, Department of Rheumatology in Östergötland.
    Inducible nitric oxide synthase (NOS II) is constitutive in human neutrophils2003In: APMIS, ISSN 0903-4641, Vol. 111, no 10, p. 963-968Article in journal (Refereed)
    Abstract [en]

    The objective was to study the expression of inducible nitric oxide synthase (NOS II) in and NO production by human blood neutrophils and in in vivo exudated neutrophils. Cellular expression of NOS II was evaluated by flow cytometry in whole blood, in isolated blood neutrophils, and in neutrophils obtained by exudation in vivo into skin chambers. Neutrophil NOS II was also demonstrated by Western blotting. Uptake of 3H-labelled L-arginine was studied in vitro and NOS activity measured in a whole cell assay by the conversion of 3H-arginine to 3H-citrulline. In contrast to unseparated blood cells, NOS II was demonstrable both in isolated blood neutrophils and exudated cells. The failure to detect NOS II by flow cytometry in whole blood cells thus proved to be due to the quenching effect of hemoglobin. Western blotting revealed a 130 kD band corresponding to NOS II in isolated blood neutrophils, but detection was dependent on diisopropylfluorophosphate for proteinase inhibition. L-arginine was taken up by neutrophils, but enzymatic activity could not be demonstrated. We conclude that human neutrophils constitutively express NOS II, but that its demonstration by FITC-labelling is inhibited by hemoglobin-mediated quenching in whole blood samples.

  • 10.
    Cedergren, Jan
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Rheumatology . Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Skogh, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Rheumatology . Linköping University, Faculty of Health Sciences.
    Inducible nitric oxide synthase is expressed in synovial fluid granulocytes2002In: Clinical Experimental Immunology, ISSN 0009-9104, Vol. 130, p. 150-155Article in journal (Refereed)
    Abstract [en]

    The objective of the study was to evaluate the NO-producing potential of synovial fluid (SF) cells. SF from 15 patients with arthritis was compared with blood from the same individuals and with blood from 10 healthy controls. Cellular expression of inducible nitric oxide synthase (iNOS) was analysed by flow cytometry. High-performance liquid chromatography was used to measure L-arginine and L-citrulline. Nitrite and nitrate were measured colourimetrically utilizing the Griess' reaction. Compared to whole blood granulocytes in patients with chronic arthritis, a prominent iNOS expression was observed in SF granulocytes (P < 0.001). A slight, but statistically significant, increase in iNOS expression was also recorded in lymphocytes and monocytes from SF. L-arginine was elevated in SF compared to serum (257 ± 78 versus 176 ± 65 µmol/l, P = 0.008), whereas a slight increase in L-citrulline (33 ± 11 versus 26 ± 9 µmol/l), did not reach statistical significance. Great variations but no significant differences were observed comparing serum and SF levels of nitrite and nitrate, respectively, although the sum of nitrite and nitrate tended to be elevated in SF (19.2 ± 20.7 versus 8,6 ± 6.5 µmol/l,P = 0.054). Synovial fluid leucocytes, in particular granulocytes, express iNOS and may thus contribute to intra-articular NO production in arthritis.

  • 11.
    Cedergren, Jan
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Rheumatology . Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Skogh, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Rheumatology . Linköping University, Faculty of Health Sciences.
    Intracellular oxidative activation in synovial fluid neutrophils from patients with rheumatoid arthritis but not from other arthritis patients2007In: Journal of Rheumatology, ISSN 0315-162X, E-ISSN 1499-2752, Vol. 34, no 11, p. 2162-2170Article in journal (Refereed)
    Abstract [en]

    Objective: To compare total and intracellular oxidative activation of blood and synovial fluid (SF) neutrophils from patients with rheumatoid arthritis (RA) and other arthritides with blood donor neutrophils.

    Methods: Peripheral blood and SF samples were obtained from 26 gonarthritis patients (13 RA, 13 non-RA) attending the rheumatology unit for therapeutic joint aspiration. Isolated neutrophils were stimulated by a formylated tripeptide (fMLF) or by microbeads coated with collagen-I. Formation of superoxide-anion-derived reactive oxygen species (ROS) was studied by luminol-enhanced chemiluminescence. Paired samples of blood and SF neutrophils from patients with active arthritis were compared with blood neutrophils from patients in remission and from 47 healthy blood donors.

    Results: SF neutrophils from patients with RA, but not from non-RA patients, showed high baseline intracellular ROS production. Blood neutrophils from arthritis patients in remission existed in a primed state as revealed by more rapid oxidative response after collagen-bead challenge and a more pronounced response after fMLF stimulation compared to healthy blood donors. Blood neutrophils from RA patients with ongoing gonarthritis, however, did not differ from healthy blood donors concerning oxidative activation, whereas blood neutrophils from non-RA patients with gonarthritis showed a significantly lower peak ROS production.

    Conclusions: A novel finding with pathogenetic implications in our study is that SF neutrophils from patients with RA, but not other arthritides, are activated and produce ROS intracellularly. This implies that synovial neutrophils in RA are engaged in the processing of endocytosed material.

  • 12.
    Cedergren, Jan
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Rheumatology . Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Skogh, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Rheumatology . Linköping University, Faculty of Health Sciences.
    Oxidative activation of human neutrophils by type-1-collagen-coated particles is influenced by nitric oxide production and modulated by endogenous arginase2007In: Journal of Leukocyte Biology, ISSN 0741-5400, E-ISSN 1938-3673Article in journal (Refereed)
  • 13.
    Dahlfors, Gunilla
    et al.
    Linköping University, Department of Biomedicine and Surgery, Cell biology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Arnqvist, Hans J.
    Linköping University, Department of Biomedicine and Surgery, Cell biology. Linköping University, Department of Medicine and Care, Internal Medicine. Linköping University, Faculty of Health Sciences.
    Effect of nitric oxide on vascular smooth muscle cell proliferation and insulin-like growth factor binding protein expressionManuscript (preprint) (Other academic)
    Abstract [en]

    A possible interaction between nitric oxide (NO) and the insulin-like growth factor (IGF)-system was studied in cultured rat aortic smooth muscle cells. The NO-donor SNAP markedly inhibited basal and sernm-induced DNA synthesis while addition of L-NAME, an inhibitor of endogenous NO production, had no effect. L-NAME did also not significantly affect IGF-I, angiotensin II or TGF-ß1- induced effects on DNA synthesis. IGF-I was shown to stimulate the expression of IGFBP-4 mRNA, as measured by an RNase-protection assay, and angiotensin II inhibited expression of IGFBP-2 mRNA. Addition of L-NAME did not significantly change the effect of IGF-I or angiotensin II on IGFBP mRNA expression, neither did L-NAME or SNAP affect basal expression of IGFBP-2, -4 or -6 mRNA. In conclusion, we found no evidence for interaction of NO with the IGF-system in smooth muscle cells. Nitric oxide did not regulate the expression of IGFBPs and IGF-I-induced smooth muscle cell proliferation was not affected by inhibition of endogenous NO production.

  • 14.
    Devenney, Irene
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences.
    Norrman, Gunilla
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Fälth-Magnusson, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Urinary nitric oxide excretion in infants with eczema2010In: Pediatric Allergy and Immunology, ISSN 0905-6157, E-ISSN 1399-3038, Vol. 21, no 1, p. e229-e234Article in journal (Refereed)
    Abstract [en]

    Eczema is characterized by inflammation of the skin and is commonly associated with food allergy. It has been suggested that nitric oxide (NO) is an important player in eczema, food allergy and intestinal inflammation. The aim of this study was to assess the levels of urinary NO breakdown products in infants with eczema and the effect of eczema treatment on NO levels. Ninety-four infants with eczema, 58 boys and 36 girls, with a mean age of 7.5 ± 5.2 months (mean ± s.d.) at inclusion were examined twice with an interval of 6 wk. The sum of nitrite and nitrate was measured colorimetrically in urinary samples from both visits and compared with clinical data concerning eczema severity, nutrition, gastrointestinal symptoms, asthma and skin prick positivity. The levels of NO products increased significantly from the first to the second visit: 289; 374 μm (median; IQR) vs. 457; 678 μm (median; IQR) (p < 0.001) in parallel with a significant improvement of the eczema. After eczema treatment consisting of skin care and elimination diet during the 6-wk interval between evaluations, the NO levels approached the values previously found in healthy children. The results support previous studies indicating that the homeostasis of nitrogen radicals is disturbed in childhood eczema.

  • 15.
    Forslund, Tony
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Harriet
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Nitric Oxide Regulates the Aggregation of Stimulated Human Neutrophils2000In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 274, no 2, p. 482-487Article in journal (Refereed)
    Abstract [en]

    Neutrophil aggregation is mediated by both CD18 integrin and L-selectin. Nitric oxide attenuates the integrin-mediated adhesion of neutrophils to collagen and to endothelium and may therefore affect aggregation as well. FMLP-stimulated neutrophils exposed to -arginine showed increased and prolonged aggregation, whereas cells pretreated with L-NAME did not differ from FMLP-stimulated controls. Nitric oxide is known to induce ADP ribosylation of G-actin, which inhibits polymerization. We detected equivalent levels of total F-actin in cells pretreated with -arginine or L-NAME and non-pretreated controls. However, neutrophils pretreated with -arginine and stimulated by CD18 integrin cross-linking exhibited a more limited increase in total F-actin, compared to control and L-NAME-pretreated cells. Thus at least two signaling pathways may be involved FMLP-stimulated aggregation, mediated by CD18 integrins. More specifically, it is plausible that FMLP-receptor signaling upregulates CD18 integrins and endogenous NO subsequently modulates CD18-mediated signaling to prolong aggregation, possibly through ADP-ribosylation of actin.

  • 16. Grant, C
    et al.
    Högberg, Lotta
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Norrköping.
    Fälth-Magnusson, Karin
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Linköping.
    Grodzinsky, Ewa
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Department of Health and Society, General Practice. Östergötlands Läns Landsting, Local Health Care Services in the West of Östergötland, Unit of Research and Development in Local Health Care, County of Östergötland.
    Sundqvist, Tommy
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Stenhammar, Lars
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Linköping.
    The clinical relevance of duodenal intraepithelial lymphocyte counts in children treated for disease2008In: Acta Paediatrica, ISSN 0803-5253, E-ISSN 1651-2227Article in journal (Refereed)
    Abstract [en]

      

  • 17.
    Gustafsson, Mikael
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Center, Department of Cardiology in Linköping.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Lateral diffusion of the secretory component (SC) in the basolateral membrane of the human colon carcinoma cell line HT29 assessed with fluorescence recovery after photobleaching1988In: Journal of Cellular Physiology, ISSN 0021-9541, E-ISSN 1097-4652, Vol. 137, no 3, p. 608-611Article in journal (Refereed)
    Abstract [en]

    The lateral diffusion of the secretory component (SC), acting as a receptor for dimeric IgA in the basolateral side of intestinal epithelial cells, was studied in the human colonic carcinoma cell line HT29. The HT29 cells were grown in Dulbecco's modified Eagle's medium in which galactose had been substituted for glucose to promote development of small intestine-like cells, with a distinct separation of the basolateral side from the apical surface. The SC was stained with rhodamine-labeled polyclonal anti-human SC rabbit antibodies (Ig) or Fab fragments, and the lateral mobility was assessed with the fluorescence recovery after photobleaching technique. The average lateral diffusion was consistent with a diffusion constant of 7.7 ± 2.0 (mean value ± SD; n = 29) and 7.1 ± 2.3 (n = 30) × 10−10 cm2s−1 for Ig-and Fab-labeled receptors, respectively, which is slower than lipid diffusion but is similar to that found for other membrane receptors. The corresponding values for the fraction of mobile receptors were 66 ± 13% and 71 ± 12%, respectively. Cells were labeled from the top of the culture plate, and cells adjacent to a mechanically made rift or a natural opening in the cell monolayer were labeled more strongly, confirming the microscope-based impression that the basolateral surface primarily harboured the SC receptor.

  • 18.
    Hollén, Elisabet
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Högberg, Lotta
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Linköping University, Faculty of Health Sciences.
    Laurin, Pia
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Linköping University, Faculty of Health Sciences.
    Stenhammar, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Linköping University, Faculty of Health Sciences.
    Fälth-Magnusson, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Urinary nitric oxide during one year of gluten-free diet with or without oats in children with coeliac disease2006In: Scandinavian Journal of Gastroenterology, ISSN 0036-5521, Vol. 41, no 11, p. 1272-1278Article in journal (Refereed)
    Abstract [en]

    Objective. Although in both adults and children with coeliac disease (CD) it is now recommended that oats be added to their gluten-free diet, there is still some controversy concerning the possible harmful effects of oats in some individuals. In this study concentrations of nitric oxide metabolites were repeatedly measured in the urine of children under investigation for CD, when on a gluten-free diet with or without oats.

    Material and methods. The study included 116 children, randomized to a standard gluten-free diet (GFD-std) or a gluten-free diet supplemented with wheat-free oat products (GFD-oats), over a one-year period. Small-bowel biopsy was performed at the beginning and end of the study. Morning urine samples were collected from 87 children and urinary nitrite/nitrate concentrations were monitored at 0, 3, 6, 9 and 12 months.

    Results. All patients were in clinical remission after the study period. There was a rapid decline in urinary nitrite/nitrate concentrations in both groups as early as after 3 months. No differences were seen between the study groups at any of the checkpoints. However, at the end of the study, the nitrite/nitrate values of 9 children in the GFD-oats group and 8 children in the GFD-std group had not normalized.

    Conclusions. Children with CD on a gluten-free diet with oats display a similar reduction in urinary nitrite/nitrate as those on a traditional gluten-free diet. Some children, however, still demonstrate high nitrite/nitrate excretion after one year on either diet, indicating that long-term follow-up studies of children on an oats-containing diet are needed.

  • 19.
    Hollén, Elisabet
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Holmgren Peterson, Kajsa
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Grodzinsky, Ewa
    Högberg, Lotta
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Linköping University, Faculty of Health Sciences.
    Laurin, Pia
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Linköping University, Faculty of Health Sciences.
    Stenhammar, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Linköping University, Faculty of Health Sciences.
    Fälth-Magnusson, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Coeliac children on a gluten-free diet with or without oats display equal anti-avenin antibody titres2006In: Scandinavian Journal of Gastroenterology, ISSN 0036-5521, Vol. 41, no 1, p. 42-47Article in journal (Refereed)
    Abstract [en]

    Objective. Recent studies report negligible toxicity of oats in the majority of coeliac disease (CD) patients. It has previously been shown that children with untreated CD have circulating antibodies to oats avenin. In this study we performed serial assessments of anti-avenin antibodies in children under investigation for CD on a gluten-free diet with or without oats.

    Material and methods. The study involved 116 children, randomized to a standard gluten-free diet or a gluten-free diet supplemented with oats. Sera were obtained from 86 children, 48 in the standard gluten-free group and 38 in the gluten-free oats group, of which 33 consumed at least 10 g of oats daily. IgA and IgG anti-avenin antibodies were monitored at 0, 3, 6 and 12 months. Nitric oxide metabolites were measured in 7 patients, with deviating antibody results.

    Results. There was a significant decrease in anti-avenin antibodies in both groups at the end as compared to the beginning of the study, (p<0.001), but no difference was found between the two groups. IgA titres already declined after 3 months. IgG titres, although significantly decreased, remained high in the majority of patients in both groups. Nitric oxide levels were high in four of the analysed samples.

    Conclusions. Oats per se, do not seem to produce a humoral immune reaction in children with CD when given in an otherwise gluten-free diet, indicating that the reaction requires gluten challenge. Anti-avenin antibodies were equal in the two study groups, and these findings strengthen the clinical impression that oats can be tolerated by the majority of patients with CD.

  • 20.
    Holm, Åsa
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Öberg, Åke
    Linköping University, Department of Biomedical Engineering. Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Mechanical manipulation of polymorphonuclear leukocyte plasma membranes with optical tweezers causes influx of extracellular calcium through membrane channels1999In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 37, no 3, p. 410-412Article in journal (Refereed)
    Abstract [en]

    Optical tweezers are used mechanically to manipulate the plasma membrane of polymophonuclear leukocytes attached to the bottom of a glass manipulation chamber. The laser trapping beam is dragged across the membrane of cells in calcium-containing and calcium-depleted extracellular medium. This treatment causes a significant rise in the intracellular calcium concentration compared with controls, in cells in calcium-containing medium (239.8±49.0% against 75.4±16.4%, respectively), but not in cells in calcium-depeleted medium (69.1±9.6% against 83.4±18.5%, respectively), indicating that the calcium rise is caused by an influx of calcium from the environment. The rise in calcium concentration is blocked (23.5±7.1% against 17.1±4.1%, respectively) by the addition of lansoprazole, indicating that the influx is not due to unspecific membrane damage caused by the mechanical manipulation of the cell. It can therefore be concluded that mechanical manipulation of the neutrophil membrane, in the piconewton force range exerted by the optical tweezer, does not damage the plasma membrane but stimulates a mechanically inducible, membrane channel-mediated influx of extracellular calcium.

  • 21.
    Högberg, Lotta
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Norrköping.
    Danielsson, Lars
    Norrtälje Hospital.
    Jarleman, Stefan
    Astrid Lindgren's Children Hospital.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Stenhammar, Lars
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Norrköping.
    Serum zinc in small children with coeliac disease2009In: ACTA PAEDIATRICA, ISSN 0803-5253, Vol. 98, no 2, p. 343-345Article in journal (Refereed)
    Abstract [en]

    In coeliac disease (CD) there is a gluten-induced small bowel enteropathy leading to malabsorption of various nutrients, vitamins and trace elements. Low levels of serum zinc have been reported in adults with untreated CD. In the present study we related the serum concentration of zinc to the morphology of the small bowel mucosa in 58 children, all under 4 years of age and under investigation for coeliac disease. The mean serum concentration of zinc (mean +/- SD; mu mol/L) was significantly lower in children with untreated CD (9.7 +/- 2.0) (n = 11) compared to non-coeliac children without enteropathy (15.1 +/- 2.3) (n = 16) (p &lt; 0.001), coeliac children on a gluten-free diet without enteropathy (14.2 +/- 1.6) (n = 14) (p &lt; 0.001), coeliac children on gluten challenge with enteropathy (14.1 +/- 2.1) (n = 12) (p &lt; 0.001) and coeliac children on gluten challenge without enteropathy (13.8 +/- 1.9) (n = 6) (p &lt; 0.005).

    Conclusion: Serum zinc concentration is decreased in untreated coeliac children with enteropathy and normalizes on gluten-free diet. A low serum zinc value in a child being investigated for possible CD on clinical grounds can thus be used as a complementary marker for enteropathy indicating further investigation with small bowel biopsy. The hypothetical role of zinc in the pathogenesis of CD is discussed.

  • 22.
    Högberg, Lotta
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Norrköping.
    Webb, C
    Lund University.
    Fälth-Magnusson, Karin
    Linköping University, Department of Clinical and Experimental Medicine, Pediatrics. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Centre of Paediatrics and Gynecology and Obstetrics, Department of Paediatrics in Linköping.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Danielsson, L
    Norrtalje Hospital.
    Ivarsson, A
    Umea University.
    Sandstrom, O
    Umea University.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Children with screening-detected coeliac disease show increased levels of nitric oxide products in urine2011In: ACTA PAEDIATRICA, ISSN 0803-5253, Vol. 100, no 7, p. 1023-1027Article in journal (Refereed)
    Abstract [en]

    Aim: Increased concentration of nitric oxide (NO) metabolites, nitrite and nitrate, in the urine is a strong indication of ongoing small intestinal inflammation, which is a hallmark of the enteropathy of coeliac disease (CD). It has previously been shown that children with symptomatic, untreated CD have increased levels of NO oxidation products in their urine. The aim of this study was to investigate whether screening-detected, asymptomatic coeliac children display the same urinary nitrite/nitrate pattern. Methods: In a multicenter screening study, serum samples were collected from 7208 12-year-old children without previously diagnosed CD. Sera were analysed for anti-human tissue transglutaminase (tTG) of isotype IgA. Small bowel biopsy was performed in antibody-positive children, yielding 153 new cases of CD. In the screening-detected individuals, the sum of nitrite and nitrate concentrations in the urine was analysed and used as an indicator of NO production. For comparison, 73 children with untreated, symptomatic CD were studied. Results: The nitrite/nitrate levels in children with screening-detected CD and those with untreated symptomatic CD did not differ significantly. Both groups had significantly increased urinary nitrite/nitrate concentrations compared to the children with normal small bowel biopsy (p andlt; 0.001). Conclusion: Children with screening-detected CD have increased production of NO just as children with untreated symptomatic CD. High NO metabolite levels in the urine may indicate a pathogenetic feature of CD and be a marker of major clinical importance.

  • 23.
    Idh, Jonna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Lerm, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Raffetseder, Johanna
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Eklund, Daniel
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Larsson, Marie
    Linköping University, Department of Clinical and Experimental Medicine, Clinical Microbiology. Linköping University, Faculty of Health Sciences.
    Pienaar, Elsje
    Linköping University, Department of Clinical and Experimental Medicine. Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Werngren, Jim
    Department of Preparedness, Unit of Highly Pathogenic Microorganisms, Swedish Institute for Communicable Disease Control, Sweden.
    Juréen, Pontus
    Department of Preparedness, Swedish Institute for Communicable Disease Control, Sweden.
    Ängeby, Kristian
    Department of Clinical Microbiology, Karolinska Institute, Karolinska University Hospital, Sweden.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Schön, Thomas
    Department of Infectious Diseases and Clinical Microbiology, Kalmar County Hospital, Sweden.
    Susceptibility of Clinical Strains of Mycobacterium tuberculosis to Reactive Nitrogen Species in Activated MacrophagesManuscript (preprint) (Other academic)
    Abstract [en]

    Background: Nitric oxide (NO) is produced in macrophages by the inducible NO synthase (iNOS) upon activation by pro-inflammatory cytokines. NO has been shown to be essential for the control of Mycobacterium tuberculosis infection in murine models whereas its importance in man is not as clear. There is a lack of studies regarding the susceptibility to reactive nitrogen species (RNS) in clinical strains of M. tuberculosis and the relation to first-line drug resistance, such as to isoniazid (INH). The aim of this study was to explore susceptibility to RNS and intracellular survival of clinical strains of M. tuberculosis, with or without INH resistance.

    Method: Seven clinical strains of M. tuberculosis were transformed with the pSMT1-plasmid encoding Vibrio harveyi luciferase. Survival was analysed by luminometry following exposure to the NO donor DETA/NO or peroxynitrite (SIN-1). Intracellular killing was studied in murine macrophages (RAW 264.7) activated with interferon gamma (IFN-γ) and lipopolysaccharide (LPS).

    Results: There was a significant effect on growth control of M. tuberculosis strains upon macrophage activation, which showed variability among clinical isolates. In the cell-free system, all strains showed a dose-dependent susceptibility to DETA/NO and SIN-1, and clinical strains were in general more resistant than H37Rv to DETA/NO. INH-resistant strains with an inhA mutation were significantly more tolerant to DETA/NO than inhA wild type.

    Conclusion: Reactive nitrogen species inhibited growth of clinical M. tuberculosis isolates both in an intra- and extracellular model with significant difference between strains. Increased tolerance to NO was associated with isoniazid resistance mediated by inhA.

  • 24.
    Idh, Jonna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Mekonnen, M.
    Department of Microbiology, Immunology and Parasitology, Addis Ababa University, Ethiopia.
    Abate, E.
    Armauer Hansen Research Institute, Ethiopia.
    Wedajo, W.
    Armauer Hansen Research Institute, Ethiopia.
    Werngren, J.
    Department of Preparedness, Unit of Highly Pathogenic Microorganisms, Swedish Institute for Communicable Disease Control, Sweden.
    Ängeby, K.
    Clinical Microbiology, MTC, Karolinska Institute, Karolinska University Hospital, Sweden.
    Lerm, Maria
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Elias, D.
    University of Southern Denmark, Institute of Molecular Medicine, Department of Cancer and Inflammation, Denmark.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Aseffa, A.
    Armauer Hansen Research Institute, Ethiopia.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Schön, T.
    Department of Infectious Diseases and Department of Clinical Microbiology, Kalmar County Hospital, Sweden.
    Resistance to First-Line Anti-TB Drugs is Associated with Reduced Nitric Oxide Susceptibility in Mycobacterium tuberculosis2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 1, p. e39891-Article in journal (Refereed)
    Abstract [en]

    Background and objective: The relative contribution of nitric oxide (NO) to the killing of Mycobacterium tuberculosis in human tuberculosis (TB) is controversial, although this has been firmly established in rodents. Studies have demonstrated that clinical strains of M. tuberculosis differ in susceptibility to NO, but how this correlates to drug resistance and clinical outcome is not known.

    Methods: In this study, 50 sputum smear- and culture-positive patients with pulmonary TB in Gondar, Ethiopia were included. Clinical parameters were recorded and drug susceptibility profile and spoligotyping patterns were investigated. NO susceptibility was studied by exposing the strains to the NO donor DETA/NO.

    Results: Clinical isolates of M. tuberculosis showed a dose- and time-dependent response when exposed to NO. The most frequent spoligotypes found were CAS1-Delhi and T3_ETH in a total of nine known spoligotypes and four orphan patterns. There was a significant association between reduced susceptibility to NO (>10% survival after exposure to 1mM DETA/NO) and resistance against first-line anti-TB drugs, in particular isoniazid (INH). Patients infected with strains of M. tuberculosis with reduced susceptibility to NO showed no difference in cure rate or other clinical parameters, but a tendency towards lower rate of weight gain after two months of treatment.

    Conclusion: There is a correlation between resistance to first-line anti-TB drugs and reduced NO susceptibility in clinical strains of M. tuberculosis. Further studies including the mechanisms of reduced NO susceptibility are warranted and could identify targets for new therapeutic interventions.

  • 25.
    Idh, Jonna
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Westman, Anna
    Karolinska Hospital.
    Elias, Daniel
    Armauer Hansen Research Institute.
    Moges, Feleke
    Gondar University.
    Getachew, Assefa
    Gondar University.
    Gelaw, Aschalew
    Gondar University.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Alemu, Addis
    Gondar University.
    Ayele, Belete
    Gondar University.
    Diro, Ermias
    Gondar University.
    Melese, Endalkachew
    Gondar University.
    Wondmikun, Yared
    Gondar University.
    Britton, Sven
    Karolinska Hospital.
    Stendahl, Olle
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology.
    Schön, Thomas
    Kalmar City Hospital.
    Nitric oxide production in the exhaled air of patients with pulmonary tuberculosis in relation to HIV co-infection2008In: BMC Infectious Diseases, ISSN 1471-2334, E-ISSN 1471-2334, Vol. 8, no 146Article in journal (Refereed)
    Abstract [en]

    Background: Nitric oxide (NO) is essential for host defense in rodents, but the role of NO during tuberculosis (TB) in man remains controversial. However, earlier observations that arginine supplementation facilitates anti-TB treatment, supports the hypothesis that NO is important in the host defense against TB. Local production of NO measured in fractional exhaled air (FeNO) in TB patients with and without HIV co-infection has not been reported previously. Thus, our aim was to investigate levels of FeNO in relation to clinical symptoms and urinary NO metabolites (uNO).

    Methods: In a cross sectional study, FeNO and uNO were measured and clinical symptoms, chest x-ray, together with serum levels of arginine, tumor necrosis factor alpha (TNF-alpha) and interleukin 12 (IL-12) were evaluated in sputum smear positive TB patients (HIV+/TB, n = 36, HIV-/TB, n = 59), their household contacts (n = 17) and blood donors (n = 46) from Gondar University Hospital, Ethiopia.

    Results: The proportion of HIV-/TB patients with an increased FeNO level (> 25 ppb) was significantly higher as compared to HIV+/TB patients, but HIV+/TB patients had significantly higher uNO than HIV-/TB patients. HIV+ and HIV-/TB patients both had lower levels of FeNO compared to blood donors and household contacts. The highest levels of both uNO and FeNO were found in household contacts. Less advanced findings on chest x-ray, as well as higher sedimentation rate were observed in HIV+/TB patients as compared to HIV-/TB patients. However, no significant correlation was found between FeNO and uNO, chest x-ray grading, clinical symptoms, TNF-alpha, IL-12, arginine levels or sedimentation rate.

    Conclusion: In both HIV negative and HIV co infected TB patients, low levels of exhaled NO compared to blood donors and household were observed. Future studies are needed to confirm whether low levels of exhaled NO could be a risk factor in acquiring TB and the relative importance of NO in human TB.

  • 26. Immerstrand, C
    et al.
    Nilsson, H
    Lindroth, Margaretha
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Sundqvist, Tommy
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Peterson, KH
    Magnusson, Karl-Eric
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    Confocal and electron microscopy of melanosome aggregation in Xenopus laevis melanophores2002In: Molecular Biology of the Cell, ISSN 1059-1524, E-ISSN 1939-4586, Vol. 13, p. 2664-Conference paper (Other academic)
  • 27.
    Immerstrand, Charlotte
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Hedlund, Joel
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Holmgren Peterson, Kajsa
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Image correlation spectroscopy for quantification of pigment aggregationManuscript (preprint) (Other academic)
    Abstract [en]

    In the skin of amphibia, fish, and other organisms, the distribution of the pigment granules within melanophores regulates skin colour. In this study we have applied Image Correlation Spectroscopy (ICS; Petersen et al. 1998; Petersen et al. 1993) to monitor the aggregation of pigment granules. Normally in ICS, images from confocallaser scanning rnicroscopy are used to calculate autocorrelation functions from which the density of fluorescent particles in the image, like membrane receptors, can be obtained. The present study differs from traditional ICS in that the images are obtained by light microscopy and then Gaussian filtered to give the particles the appropriate intensity profile required for ICS analysis. ICS appears to be more sensitive than particle counting and image mean intensity for quantification of the degree of pigment aggregation. This study demonstrates for the first time that ICS can be used to analyse the aggregation of non-fluorescent particles, such as pigment granules in Xenopus laevis melanophores.

  • 28.
    Immerstrand, Charlotte
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Hedlund, Joel
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, The Institute of Technology.
    Magnusson, Karl-Eric
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Holmgren-Peterson, Kajsa
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Organelle transport in melanophores analyzed by white light image correlation spectroscopy2007In: Journal of Microscopy, ISSN 0022-2720, E-ISSN 1365-2818, Vol. 225, no 3, p. 275-282Article in journal (Refereed)
    Abstract [en]

    Intracellular transport of organelles, vesicles and proteins is crucial in all eukaryotic cells, and is accomplished by motor proteins that move along cytoskeletal filaments. A widely used model of intracellular transport is Xenopus laevis melanophores. These cells help the frog to change color by redistributing melanin-containing organelles in the cytoplasm. The high contrast of the pigment organelles permits changes in distribution to be observed by ordinary light microscopy; other intracellular transport systems often require fluorescence labeling. Here we have developed white light Image Correlation Spectroscopy (ICS) to monitor aggregation and dispersion of pigment. Hitherto in ICS, images of fluorescent particles from Confocal Laser Scanning Microscopy (CLSM) have been used to calculate autocorrelation functions from which the density can be obtained. In the present study we show that ICS can be modified to enable analysis of light-microscopy images; it can be used to monitor pigment aggregation and dispersion, and distinguish between different stimuli. This new approach makes ICS applicable not only to fluorescent but also to black-and-white images from light or electron microscopy, and is thus very versatile in different studies of movement of particles on the membrane or in the cytoplasm of cells without potentially harmful fluorescence labeling and activation.

  • 29.
    Immerstrand, Charlotte
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Jager, Edwin W.H.
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Magnusson, Karl-Eric
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Lundström, Ingemar
    Linköping University, Department of Physics, Chemistry and Biology, Applied Physics. Linköping University, The Institute of Technology.
    Inganäs, Olle
    Linköping University, Department of Physics, Chemistry and Biology, Biomolecular and Organic Electronics. Linköping University, The Institute of Technology.
    Peterson, K.H.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Altered impedance during pigment aggregation in Xenopus laevis melanophores2003In: Medical and Biological Engineering and Computing, ISSN 0140-0118, E-ISSN 1741-0444, Vol. 41, no 3, p. 357-364Article in journal (Refereed)
    Abstract [en]

    Melanophores are dark-brown pigment cells located in the skin of amphibia, fish and many invertebrates. The skin colour of these organisms is regulated by the translocation of pigment organelles, and the pigment distribution can be altered by external stimuli. The ability to change colour in response to stimuli makes these cells of interest for biosensing applications. It was investigated whether pigment aggregation in Xenopus laevis melanophores can be detected by impedance measurements performed in transparent microvials. The results show that cell attachment, cell spreading and pigment aggregation all resulted in impedance changes, seen particularly at the highest frequency tested (10 kHz). The mechanisms behind the impedance changes were investigated by the addition of latrunculin or melatonin, both of which cause pigment aggregation. The latrunculin-induced aggregation was associated with cell area decrease and filamentous actin (F-actin) breakdown, processes that can influence the impedance. Lack of F-actin breakdown and an increase in cell area during melatonin-induced aggregation suggest that some other intracellular process also contributes to the impedance decrease seen for melatonin. It was shown that impedance measurements reflect not only cell attachment and cell spreading, but also intracellular events.

  • 30.
    Immerstrand, Charlotte
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Harriet
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Lindroth, Margaretha
    Linköping University, Department of Biomedicine and Surgery, Cell biology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Holmgren-Peterson, Kajsa
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Height changes associated with pigment aggregation in Xenopus laevis melanophores2004In: Bioscience Reports, ISSN 0144-8463, E-ISSN 1573-4935, Vol. 24, no 3, p. 203-214Article in journal (Refereed)
    Abstract [en]

    Melanophores are pigment cells found in the skin of lower vertebrates. The brownish-black pigment melanin is stored in organelles called melanosomes. In response to different stimuli, the cells can redistribute the melanosomes, and thereby change colour. During melanosome aggregation, a height increase has been observed in fish and frog melanophores across the cell centre. The mechanism by which the cell increases its height is unknown. Changes in cell shape can alter the electrical properties of the cell, and thereby be detected in impedance measurements. We have in earlier studies of Xenopus laevis melanophores shown that pigment aggregation can be revealed as impedance changes, and therefore we were interested in investigating the height changes associated with pigment aggregation further. Accordingly, we quantified the changes in cell height by performing vertical sectioning with confocal microscopy. In analogy with theories explaining the leading edge of migrating cells, we investigated the possibility that the elevation of plasma membrane is caused by local swelling due to influx of water through HgC12-sensitive aquaporins. We also measured the height of the microtubule structures to assess whether they are involved in the height increase. Our results show that pigment aggregation in X. laevis melanophores resulted in a significant height increase, which was substantially larger when aggregation was induced by latrunculin than with melatonin. Moreover, the elevation of the plasma membrane did not correlate with influx of water through aquaporins or formation of new microtubules, Rather, the accumulation of granules seemed to drive the change in cell height.

  • 31. Johansson, AG
    et al.
    Sundqvist, Tommy
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology.
    Skogh, Thomas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Rheumatology. Östergötlands Läns Landsting, Centre for Medicine, Department of Rheumatology in Östergötland.
    IgG immune complex binding to and activation of liver cells.1999In: International Archives of Allergy and Immunology, ISSN 1018-2438, E-ISSN 1423-0097, Vol. 121, p. 329-336Article in journal (Refereed)
  • 32.
    Johansson, AG
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology.
    Sundqvist, Tommy
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology.
    Skogh, Thomas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Rheumatology. Östergötlands Läns Landsting, Centre for Medicine, Department of Rheumatology in Östergötland.
    IgG immune complex binding to and activation of liver cells. An in vitro study with IgG immune complexes, Kupffer cells, sinusoidal endothelial cells and hepatocytes2000In: International Archives of Allergy and Immunology, ISSN 1018-2438, E-ISSN 1423-0097, Vol. 121, no 4, p. 329-336Article in journal (Refereed)
    Abstract [en]

    Background/Aims: The aim was to study IgG immune complex (IC) binding to isolated hepatocytes, Kupffer cells (KCs) and sinusoidal endothelial cells (SECs). Further, we wished to analyze the capacity of IgG ICs to induce release of reactive oxygen metabolites by the IC-binding liver cells. Methods: ICs were formed between 125I-tyramine-cellobiose-labelled dinitrophenyl-conjugated human serum albumin (125I-TC-DNP10HSA) and polyclonal rabbit IgG antibodies. Binding of ICs to different rat liver cells in suspension was studied at 4░C. Production of reactive oxygen metabolites was measured by luminol-enhanced chemiluminescence at 37░C. Results: IgG mediated binding of 125I-TC-DNP10HSA to both KCs and SECs, but not to hepatocytes. The binding showed saturation kinetics and was blocked by an excess of unlabelled IgG-ICs. IgG-ICs activated KCs, but not SECs, to a chemiluminescence response. Conclusions: Both KCs and SECs bind IgG-ICs in vitro, probably via Fc receptor interaction. IgG-ICs activate KCs to produce reactive oxygen metabolites. The binding of IgG-ICs to isolated hepatocytes is small.

  • 33.
    Johansson, Anders
    et al.
    Linköping University, Department of Biomedical Engineering, Physiological Measurements. Linköping University, The Institute of Technology.
    Kuiper, Jan-Herman
    Keele University, England Robert Jones and Agnes Hunt Orthopaed Hospital, England .
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Persson, Fredrik
    BioOptico AB, Sweden .
    Speier, Craig
    ConMedical Linvatec, CA USA .
    DAlfonso, David
    ConMedical Linvatec, CA USA .
    Richardson, James B
    Keele University, England Robert Jones and Agnes Hunt Orthopaed Hospital, England .
    Öberg, Åke
    Linköping University, Department of Biomedical Engineering, Physiological Measurements. Linköping University, The Institute of Technology.
    Spectroscopic Measurement of Cartilage Thickness in Arthroscopy: Ex Vivo Validation in Human Knee Condyles2012In: Arthroscopy: The Journal of Arthroscopy And Related, ISSN 0749-8063, E-ISSN 1526-3231, Vol. 28, no 10, p. 1513-1523Article in journal (Refereed)
    Abstract [en]

    Purpose: To evaluate the accuracy of articular cartilage thickness measurement when implementing a new technology based on spectroscopic measurement into an arthroscopic camera. Methods: Cartilage thickness was studied by ex vivo arthroscopy at a number of sites (N = 113) in human knee joint osteoarthritic femoral condyles and tibial plateaus, removed from 7 patients undergoing total knee replacement. The arthroscopic image spectral data at each site were used to estimate cartilage thickness. Arthroscopically derived thickness values were compared with reference cartilage thickness as measured by 3 different methods: needle penetration, spiral computed tomography scanning, and geometric measurement after sample slicing. Results: The lowest mean error (0.28 to 0.30 mm) in the regression between arthroscopic and reference cartilage thickness was seen for reference cartilage thickness less than 1.5 mm. Corresponding values for cartilage thickness less than 2.0 and 2.5 mm were 0.32 to 0.40 mm and 0.37 to 0.47 mm, respectively. Cartilage thickness images-created by pixel-by-pixel regression model calculations applied to the arthroscopic images-were derived to demonstrate the clinical use of a camera implementation. Conclusions: On the basis of this investigation on osteoarthritic material, when one is implementing the spectroscopic method for estimating cartilage thickness into an arthroscopic camera, errors in the range of 0.28 to 0.30 mm are expected. This implementation does not, however, influence the fact that the spectral method performs less well in the cartilage thickness region from 1.5 to 2.5 mm and cannot assess cartilage thicker than 2.5 mm. Clinical Relevance: Imaging cartilage thickness directly in the arthroscopic camera video stream could serve as an interesting image tool for in vivo cartilage quality assessment, in connection with cartilage diagnosis, repair, and follow-up.

  • 34.
    Johansson, Anders
    et al.
    Linköping University, Department of Biomedical Engineering. Linköping University, The Institute of Technology.
    Sundqvist, Tommy
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology.
    Kuiper, J.-H.
    Keele University School of Medicine, Keele, UK .
    Öberg, Åke
    Linköping University, Department of Biomedical Engineering. Linköping University, The Institute of Technology.
    A spectroscopic approach to imaging and quantification of cartilage lesions in human knee joints2011In: Physics in Medicine and Biology, ISSN 0031-9155, E-ISSN 1361-6560, Vol. 56, no 6, p. 1865-1878Article in journal (Refereed)
    Abstract [en]

    We have previously described a technology based on diffuse reflectance of broadband light for measuring joint articular cartilage thickness, utilizing that optical absorption is different in cartilage and subchondral bone. This study is the first evaluation of the technology in human material. We also investigated the prospects of cartilage lesion imaging, with the specific aim of arthroscopic integration. Cartilage thickness was studied ex vivo in a number of sites (n = 87) on human knee joint condyles, removed from nine patients during total knee replacement surgery. A reflectance spectrum was taken at each site and the cartilage thickness was estimated using the blue, green, red and near-infrared regions of the spectrum, respectively. Estimated values were compared with reference cartilage thickness values (taken after sample slicing) using an exponential model. Two-dimensional Monte Carlo simulations were performed in a theoretical analysis of the experimental results. The reference cartilage thickness of the investigated sites was 1.60 ± 1.30 mm (mean ± SD) in the range 0–4.2 mm. Highest correlation coefficients were seen for the calculations based on the near-infrared region after normalization to the red region (r = 0.86) and for the green region (r = 0.80).

  • 35.
    Johansson, Anders
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Sundqvist, Tommy
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology.
    Kuiper, J-H
    Inst of Science and Technology in Medicine Keele University Medical School, UK.
    Öberg, Åke
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    IN VITRO Imaging of human cartilage - contrast improvement by optical wavelength selection2005In: Nordic Baltic Conference Biomedical Engineering and Medical Physics,2005, Umeå: IFMBE , 2005, p. 172-Conference paper (Refereed)
  • 36.
    Johansson, Anders
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Öberg, Åke
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Physiological Measurements.
    Sundqvist, Tommy
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology.
    Sundberg, Mikael
    Linköping University, The Institute of Technology. Linköping University, Department of Biomedical Engineering, Biomedical Instrumentation.
    Assessment of cartilage thickness utilising reflectance spectroscopy2002In: Nordic Baltic Conference on Biomedical Engineering,2002, 2002Conference paper (Refereed)
    Abstract [en]

      

  • 37.
    Laurin, Pia
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Pediatrics. Linköping University, Faculty of Health Sciences.
    Fälth-Magnusson, Karin
    Linköping University, Department of Molecular and Clinical Medicine, Pediatrics. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Increase in nitric oxide urinary products during gluten challenge in children with coeliac disease2003In: Scandinavian Journal of Gastroenterology, ISSN 0036-5521, E-ISSN 1502-7708, Vol. 38, no 1, p. 55-60Article in journal (Refereed)
    Abstract [en]

    Background: Coeliac disease is a gluten-sensitive enteropathy where pro-inflammatory cytokines and excess nitric oxide (NO) production can contribute to mucosal damage. NO urinary products are elevated in coeliac children on a gluten diet, but it is not known how rapidly this increase develops after gluten exposure.

    Methods: Oral gluten challenge was performed in 25 children whose families kept a daily record of gluten intake and symptoms. Blood was analysed monthly for antigliadin (AGA) and endomysium antibodies (EMA). Urine was analysed every second week for NO products, i.e. the sum of nitrite and nitrate was measured with a colorimetric method. We performed a third biopsy when clinical symptoms indicated a relapse. Median age at the post-challenge biopsy was 3.8 (2.7-8.8) years.

    Results: Signs of morphological or serological relapse were seen in all children. Mean daily gluten intake was 0.10 (range 0.02-0.26) g/kg bodyweight. Median NO level was doubled and significantly higher after 4 weeks of challenge but not after 2 weeks. EMA, but not AGA levels, correlated positively with NO. Intraepithelial lymphocyte count was significantly higher in the post-challenge biopsy, but did not correlate with the NO levels.

    Conclusions: NO products in urine increased during gluten challenge. EMA levels reflected severity of mucosal damage, and NO products reflected the inflammatory response, which was doubled after 4 weeks of challenge. The NO analysis is simple and non-traumatic for the child. It can be performed repeatedly during investigation of children with suspected coeliac disease.

  • 38.
    Loitto, Vesa
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Nitric oxide induces dose-dependent changes in [Ca2+](i), morphology and migration of human neutrophils. in MOLECULAR BIOLOGY OF THE CELL, vol 9, issue , pp 290A-290A1998In: MOLECULAR BIOLOGY OF THE CELL, American Society for Cell Biology , 1998, Vol. 9, p. 290A-290AConference paper (Refereed)
    Abstract [en]

    n/a

  • 39.
    Loitto, Vesa-Matti
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology . Linköping University, Faculty of Health Sciences.
    Gustafsson, Mikael
    Linköping University, Department of Medicine and Care. Linköping University, Faculty of Health Sciences.
    Neutrophil leukocyte motility requires directed water influx2002In: Journal of Leukocyte Biology, ISSN 0741-5400, E-ISSN 1938-3673, Vol. 71, no 2, p. 212-222Article in journal (Refereed)
    Abstract [en]

    The ability of neutrophils to sense and move to sites of infection is essential for our defense against pathogens. For motility, lamellipodium extension and stabilization are prerequisites, but how cells form such membrane protrusions is still obscure. Using contrast-enhanced video microscopy and Transwell® assays, we show that water-selective aquaporin channels regulate lamellipodium formation and neutrophil motility. Addition of anti-aquaporin-9 antibodies, HgCl2, or tetraethyl ammonium inhibited the function(s) of the channels and blocked motility-related shape changes. On human neutrophils, aquaporin-9 preferentially localized to the cell edges, where N-formyl peptide receptors also accumulated, as assessed with fluorescence microscopy. To directly visualize water fluxes at cell edges, cells were loaded with high dilution-sensitive, self-quenching concentrations of fluorophore. In these cells, motile regions always displayed increased fluorescence compared with perinuclear regions. Our observations provide the first experimental support for motility models where water fluxes play a pivotal role in cell-volume increases accompanying membrane extensions.

  • 40.
    Loitto, Vesa-Matti
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Nilsson, Harriet
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Magnusson, Karl-Eric
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Nitric oxide induces dose-dependent CA2+ transients and causes temporal morphological hyperpolarization in human neutrophils2000In: Journal of cellular physiology, ISSN 0021-9541, Vol. 182, no 3, p. 402-413Article in journal (Refereed)
    Abstract [en]

    We exposed adherent neutrophils to the nitric oxide (NO)-radical donors S-nitroso-N-acetylpenicillamine (SNAP), S-nitrosoglutathione (GSNO), and sodium nitroprusside (SNP) to study the role of NO in morphology and Ca(2+) signaling. Parallel to video imaging of cell morphology and migration in neutrophils, changes in intracellular free Ca(2+) ([Ca(2+)](i)) were assessed by ratio imaging of Fura-2. NO induced a rapid and persistent morphological hyperpolarization followed by migrational arrest that usually lasted throughout the 10-min experiments. Addition of 0.5-800 microM SNAP caused concentration-dependent elevation of [Ca(2+)](i) with an optimal effect at 50 microM. This was probably induced by NO itself, because no change in [Ca(2+)](i) was observed after treatment with NO donor byproducts, i.e. D-penicillamine, glutathione, or potassium cyanide. Increasing doses of SNAP (>/=200 microM) attenuated the Ca(2+) response to the soluble chemotactic stimulus formyl-methionyl-leucyl-phenylalanine (fMLP), and both NO- and fMLP-induced Ca(2+) transients were abolished at 800 microM SNAP or more. In kinetic studies of fluorescently labeled actin cytoskeleton, NO markedly reduced the F-actin content and profoundly increased cell area. Immunoblotting to investigate the formation of nitrotyrosine residues in cells exposed to NO donors did not imply nitrosylation, nor could we mimic the effects of NO with the cell permeant form of cGMP, i.e., 8-Br-cGMP. Hence these processes were probably not the principal NO targets. In summary, NO donors initially increased neutrophil morphological alterations, presumably due to an increase in [Ca(2+)](i), and thereafter inhibited such shape changes. Our observations demonstrate that the effects of NO donors are important for regulation of cellular signaling, i.e., Ca(2+) homeostasis, and also affect cell migration, e.g., through effects on F-actin turnover. Our results are discussed in relation to the complex mechanisms that govern basic cell shape changes, required for migration.

  • 41.
    Nayeri, Fariba
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Holmgren Peterson, Kajsa
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Perskvist, Nasrin
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Forsberg, Pia
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Peterson, Curt
    Linköping University, Department of Medicine and Care, Pharmacology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    An in vitro model for assessment of the biological activity of hepatocyte growth factor2007In: Growth Factors, ISSN 0897-7194, E-ISSN 1029-2292, Vol. 25, no 1, p. 33-40Article in journal (Refereed)
    Abstract [en]

    Hepatocyte growth factor (HGF) is a multifunctional growth factor with potent wound-healing properties that functions in the healing of chronic injuries. However, there may be a loss of HGF activity in certain chronic cases; this might be indicated by the presence of high amounts of HGF in body fluids and by the elevated expression of the HGF receptor in tissue biopsies. In such cases, a reliable means of assessing the activity of endogenous HGF would be valuable in allowing clinicians to decide if treatment with HGF would be useful. In this study, we developed an in vitro wound assay that used a mouse skin epithelial cell line to evaluate the biological activity of HGF. We showed that HGF accelerated the motility of the epithelial cells in a dose-dependent fashion with high sensitivity and specificity. This in vitro assay might be used to determine the activity of both endogenous and recombinant HGF.

  • 42.
    Nayeri, Fariba
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Olsson, Hans
    Linköping University, Department of Neuroscience and Locomotion, Pathology. Linköping University, Faculty of Health Sciences.
    Peterson, Curt
    Linköping University, Department of Medicine and Care, Pharmacology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Hepatocyte growth factor, expression, concentration and biological activity in chronic leg ulcers2005In: Journal of dermatological science (Amsterdam), ISSN 0923-1811, E-ISSN 1873-569X, Vol. 37, no 2, p. 75-85Article in journal (Refereed)
    Abstract [en]

    Background:

    Hepatocyte growth factor (HGF) is a multifunctional cytokine that is involved in recovery process after organ injuries.

    Objective:

    We studied HGF and the membrane bound receptor, c-met locally in patients who suffered from chronic leg ulcers (≥1 year) caused by venous insufficiency.

    Methods:

    Skin biopsies from the edge of the ulcers were taken from patients (n = 13) and studied by immunohistochemical staining for detection of HGF and c-met. Skin biopsies from healthy volunteers (n = 10) were used as the control material. Ulcer secretion from chronic ulcers (n = 11) was examined for the presence of HGF by ELISA and the concentration of HGF was compared with acute ulcers in healthy controls (n = 10) and in patients operated for a non-invasive breast cancer (n = 12).

    Results:

    We observed that c-met expression in the ulcer area increased significantly in chronic ulcers compared to controls (p = 0.005). Concentration of ulcer-HGF in the patients with chronic ulcer was significantly higher than acute ulcers (p < 0.01). The biological activity of HGF in ulcer secret was assessed in-vitro in transferred, mouse skin epithelial cell monolayer. Enhanced migration and morphologic changes were seen after adding ulcer secret from acute ulcers (>1 ng/mL) that was inhibited by anti-HGF antibodies. No biological activity was observed by adding ulcer secret from chronic ulcers irrespective HGF concentration.

    Conclusion:

    We conclude that in chronic skin ulcers decreased biological activity of endogenous HGF and overexpression of c-met is seen which might explain fibrosis and delayed recovery. Administration of exogenous active HGF might contribute to accelerated healing in these patients.

  • 43.
    Nayeri, Fariba
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Olsson, Hans
    Linköping University, Department of Neuroscience and Locomotion, Pathology. Linköping University, Faculty of Health Sciences.
    Söderström, Claes
    Department of Infectious Diseases, County Hospital in Kalmar, Sweden.
    Forsberg, Pia
    Linköping University, Department of Clinical and Experimental Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Brudin, Lars
    Department of Clinical Physiology, County Hospital in Kalmar, Sweden.
    Peterson, Curt
    Linköping University, Department of Medicine and Care, Pharmacology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Hepatocyte growth factor in chronic leg ulcers – no biological activity – no improvement2005In: Journal of dermatological science (Amsterdam), ISSN 0923-1811, E-ISSN 1873-569X, Vol. 39, no 1, p. 62-64p. 62-64Article in journal (Other academic)
    Abstract [en]

    No abstract available.

  • 44.
    Nayeri, Fariba
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Perskvist, Nasrin
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Holmgren-Pettersson, Kajsa
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Forsberg, Pia
    Linköping University, Department of Molecular and Clinical Medicine, Infectious Diseases. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Hepatocyte growth factor accelerates restitution of damaged mouse melanocyte monolayer in vitroManuscript (preprint) (Other academic)
    Abstract [en]

    In a recent pilot study we observed enhanced wound repair properties in chronic leg ulcers after HGF administration. The aim of the present study was to assess the mechanism of HGF in the wound-healing process by an in vitro study of HGF on a transformed mouse skin epithelial cell line (CCL-53. 1) that expresses the HGF receptor, c-Met. HGF did not enhance cell proliferation, judged by [3H}thymidine incorporation. The restitution of injured epithelial cells was significantly increased by HGF. This effect was dose-dependant, beginning at low concentrations (1ng/ml) of HGF, and was inhibited by heparin. HGF enhanced migration of epithelial cells compared to untreated controls. The actin structure was changed by HGF, with less F-actin in the dense peripheral structures compared to untreated cells. Corresponding morphological changes in cells were found showing spread morphology with smaller intracellular spaces after HGF addition. We conclude that HGF may contribute to restitution of the damaged mouse epithelial cell monolayer by morphologic changes and enhanced motility of cells towards the injured area.

  • 45.
    Nilsson, Harriet M.
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Holmgren Peterson, Kajsa
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Svensson, Samuel P. S.
    Linköping University, Department of Medicine and Care, Pharmacology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    HgCl2-sensitive aquaporins are not involved in melanosome aggregation in Xenopus laevis melanophoresManuscript (preprint) (Other academic)
    Abstract [en]

    Melanophores are cells specialized for transport of pigment-filled organelles called melanosomes. Melanosomes are aggregated in the center of a melanophore or dispersed throughout the cytoplasm by motor proteins moving along the actin and microtubule cytoskeleton. In angelfish (Pterophyllum scalare), aggregation of melanosomes (as compared to dispersion) increases the height of the central part of melanophores by 300%. Our objective was to detennine whether such a height increase also occurs in frog (Xenopus laevis) melanophores. In analogy with theories explaining the leading edge of migrating cells, we investigated the possibility that elevation of the melanophore plasma membrane is due to local swelling caused by influx of water through HgCl2-sensitive aquaporins and subsequent polymerization of actin. Confocal microscopy revealed a 30% increase in height in X. laevis melanophores during melatonin-induced aggregation. This was not due to actin polymerization, because it also occurred when aggregation was induced by the polymerization inhibitor latrunculin B. The nitric oxide (NO) synthase inhibitor L-NAME induced dispersion and lowered the plasma membrane, which suggests that NO is involved in the upward movement. Furthermore, neither dispersion nor aggregation was affected by inhibition of water flux through HgCl2 sensitive aquaporins. Together, these observations imply that melanosomes in X. laevis melanophores are driven upwards during aggregation by a mechanism other than actin polymerization, possibly involving microtubules, intermediate filaments, or a motor protein that may be regulated by NO. Furthermore, influx of water through HgCl2-sensitive aquaporins is probably not necessary for aggregation-induced elevation of the cell membrane, because both aggregation and dispersion can occur in the presence of HgCl2.

  • 46.
    Nilsson, Harriet M.
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Karlsson, Annika M.
    Linköping University, Department of Medicine and Care, Pharmacology. Linköping University, Faculty of Health Sciences.
    Loitto, Vesa-Matti
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Svensson, Samuel P.S.
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Nitric oxide modulates intracellular translocation of pigment organelles in Xenopus laevis melanophores2000In: Cell Motility and the Cytoskeleton, ISSN 0886-1544, E-ISSN 1097-0169, Vol. 47, no 3, p. 209-218Article in journal (Refereed)
    Abstract [en]

    Pigment organelles in Xenopus laevis melanophores are used by the animal to change skin color, and they provide a good model for studying intracellular organelle transport. Movement of organelles and vesicles along the cytoskeleton is essential for many processes, such as axonal transport, endocytosis, and intercompartmental trafficking. Nitric oxide (NO) is a signaling molecule that plays a role in, among other things, relaxation of blood vessels, sperm motility, and polymerization of actin. Our study focused on the effect NO exerts on cytoskeleton-mediated transport, which has previously received little attention. We found that an inhibitor of NO synthesis, N-nitro-L-arginine methyl ester (L-NAME), reduced the melatonin-induced aggregation of the pigment organelles, melanosomes. Preaggregated melanosomes dispersed after treatment with L-NAME but not after exposure to the inactive stereoisomer (D-NAME) or the substrate for NO synthesis (L-arginine). Signal transduction by NO can be mediated through the activation of soluble guanylate cyclase (sGC), which leads to increased production of cGMP and activation of cGMP-dependent kinases (PKG). We found that both the sGC inhibitor 1H-(1,2,4) oxadiazolo(4,3-a)quinoxalin-1-one (ODQ) and the cGMP analogue 8-bromoguanosine 3′:5′-cyclic monophosphate (8-Br-cGMP) reduced melanosome aggregation, whereas the PKG inhibitor KT582 did not. Our results demonstrate that melanosome aggregation depends on synthesis of NO, and NO deprivation causes dispersion. It seems, thus, as if NO and cGMP are essential and can regulate melanosome translocation.

  • 47.
    Nilsson, Harriet M.
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Svensson, Samuel
    Linköping University, Department of Medicine and Care, Pharmacology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    L-NAME-induced dispersion of melanosomes in melanophores activates PKC, MEK and ERK12001In: Pigment Cell Research, ISSN 1755-1471, E-ISSN 1755-148X, Vol. 14, no 6, p. 450-455Article in journal (Refereed)
    Abstract [en]

    Melanosome movement represents a good model of cytoskeleton-mediated transport of organelles in eukaryotic cells. We recently observed that inhibiting nitric oxide synthase (NOS) with Nω-nitro-l-arginine methyl ester (l-NAME) induced dispersion in melanophores pre-aggregated with melatonin. Activation of cyclic adenosine 3′,5′-monophosphate (cAMP)-dependent protein kinase (PKA) or calcium-dependent protein kinase (PKC) is known to cause dispersion. Also, PKC and NO have been shown to regulate the mitogen/extracellular signal-regulated kinase (MEK)-ERK pathway. Accordingly, our objective was to further characterize the signaling pathway of l-NAME-induced dispersion. We found that the dispersion was decreased by staurosporine and PD98059, which respectively inhibit PKC and MEK, but not by the PKA inhibitor H89. Furthermore, Western blotting revealed that ERK1 kinase was phosphorylated in l-NAME-dispersed melanophores. l-NAME also caused dispersion in latrunculin-B-treated cells, suggesting that this effect is not due to inhibition of the melatonin signaling pathway. Summarizing, we observed that PKC and MEK inhibitors decreased the l-NAME-induced dispersion, which caused phosphorylation of ERK1. Our results also suggest that NO is a negative regulator of phosphorylations that leads to organelle transport.

  • 48. Rodriguez-Diaz, Jesús
    et al.
    Banasaz, Mahanez
    Istrate, Claudia
    Buesa, Javier
    Lundgren, Ove
    Espinoza, Felix
    Sundqvist, Tommy
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology.
    Rottenberg, Martin
    Svensson, Lennart
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Molecular and Clinical Medicine, Molecular Virology.
    Role of nitric oxide during rotavirus infection2006In: Journal of Medical Virology, ISSN 0146-6615, E-ISSN 1096-9071, Vol. 78, no 7, p. 979-985Article in journal (Refereed)
    Abstract [en]

    The pathophysiological mechanisms behind rotavirus-induced diarrhoea still remain incomplete. Current views suggest that the non-structural protein 4 (NSP4) of rotavirus and the enteric nervous system (ENS) participate in water secretion and diarrhoea. In the present work the role of nitric oxide (NO) in rotavirus infection and disease has been studied in vitro, mice and humans. Incubation of human intestinal epithelial cells (HT-29) with purified NSP4 but not with infectious virus produced NO2/NO3 accumulation in the incubation media. The NSP4-induced release of NO metabolites occurred within the first minutes after the addition of the toxin. Mice infected with murine rotavirus (strain EDIM) accumulated NO2/NO3 in the urine at the onset for diarrhoea. Following rotavirus infection, inducible nitric oxide synthetase (iNOS) mRNA was upregulated in ileum, but not in duodenum or jejunum of newborn pups within 5 days post-infection. A prospective clinical study including 46 children with acute rotavirus infection and age-matched controls concluded that rotavirus infection stimulates NO production during the course of the disease (P < 0.001). These observations identify NO as an important mediator of host responses during rotavirus infection. © 2006 Wiley-Liss, Inc.

  • 49.
    Sandström, Per
    et al.
    Linköping University, Department of Biomedicine and Surgery, Surgery. Linköping University, Faculty of Health Sciences.
    Gasslander, Thomas
    Department of Surgery, Vrinnevi Hospital, Norrköping, Sweden.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Franke, Jonas
    Department of Surgery, Vrinnevi Hospital, Norrköping, Sweden.
    Svanvik, Joar
    Linköping University, Department of Biomedicine and Surgery, Surgery. Linköping University, Faculty of Health Sciences.
    Depletion of serum L-arginine in patients with acute pancreatitis2003In: Pancreas, ISSN 0885-3177, E-ISSN 1536-4828, Vol. 27, no 3, p. 261-266Article in journal (Refereed)
    Abstract [en]

    Introduction: Acute pancreatitis may be initiated by interference with the pancreatic outflow to the duodenum. This flow is normally regulated by reflex relaxation of the sphincter of Oddi in which nitric oxide is an important mediator.

    Aim: To test the hypothesis that acute pancreatitis involves a depletion in serum l-arginine resulting in impaired production of nitric oxide.

    Methods: We measured serum l-arginine and l-citrulline and urinary nitrite/nitrate concentrations 1 to 3 days after the onset of symptoms in 11 patients with gallstone pancreatitis, 10 patients with alcoholic pancreatitis, and 6 patients with idiopathic pancreatitis. We compared their results with those from control groups of 13 healthy blood donors, 9 patients fasting before hernia operations, 8 patients with acute cholecystitis, and 9 alcoholic subjects but no pancreatitis. Serum arginine and citrulline concentrations were measured with high performance liquid chromatography, and urinary nitrite/nitrate spectrophotometrically.

    Results: Patients with acute pancreatitis, of whatever cause, had lower serum l-arginine and l-citrulline concentrations than controls. Patients with gallstone and idiopathic pancreatitis also have reduced urinary concentrations of nitrite and nitrate but this was not seen in patients with alcoholic pancreatitis.

    Conclusions: L-arginine and l-citrulline concentrations are depleted in the serum of patients with acute pancreatitis. Reduced urinary nitrite and nitrate in gallstone pancreatitis indicate that there is a defect formation of nitric oxide. This may cause a functional obstruction of the outflow of pancreatic juice to the duodenum and so may be involved in the pathophysiology of acute pancreatitis.

  • 50.
    Sandström, Per
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Surgery . Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Trulsson, Lena
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Surgery .
    Gasslander, Thomas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Surgery . Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Sundqvist, Tommy
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology .
    von Dobeln, U.
    Department of Laboratory Medicine Karolinska University Hospital Huddinge, Stockholm.
    Svanvik, Joar
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Clinical and Experimental Medicine, Surgery . Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Surgery in Östergötland.
    Serum amino acid profile in patients with acute pancreatitis2008In: Amino Acids, ISSN 0939-4451, E-ISSN 1438-2199, Vol. 35, no 1, p. 225-231Article in journal (Refereed)
    Abstract [en]

    Patients in the early phase of acute pancreatitis (AP) have reduced serum levels of arginine and citrulline. This may be of patho-biological importance, since arginine is the substrate for nitric oxide, which in turn is involved in normal pancreatic physiology and in the inflammatory process. Serum amino acid spectrum was measured daily for five days and after recovery six weeks later in 19 patients admitted to the hospital for acute pancreatitis. These patients had abnormal levels of most amino acids including arginine, citrulline, glutamine and glutamate. Phenylalanine and glutamate were increased, while arginine, citrulline, ornithine and glutamine were decreased compared to levels after recovery. NO2/NO3 concentration in the urine, but not serum arginase activity, was significantly increased day 1 compared to day 5 after admission. Acute pancreatitis causes a disturbance of the serum amino acid spectrum, with possible implications for the inflammatory process and organ function both in the pancreas and the gut. Supplementation of selected amino acids could possibly be of value in this severe condition. © 2007 Springer-Verlag.

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