| 1. |
- Hagbom, Marie, et al.
(author)
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Rotavirus Stimulates Release of Serotonin (5-HT) from Human Enterochromaffin Cells and Activates Brain Structures Involved in Nausea and Vomiting
- 2011
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In: PLOS PATHOGENS. - : Public Library of Science (PLoS). - 1553-7366 .- 1553-7374. ; 7:7
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Journal article (peer-reviewed)abstract
- otavirus (RV) is the major cause of severe gastroenteritis in young children. A virus-encoded enterotoxin, NSP4 is proposed to play a major role in causing RV diarrhoea but how RV can induce emesis, a hallmark of the illness, remains unresolved. In this study we have addressed the hypothesis that RV-induced secretion of serotonin (5-hydroxytryptamine, 5-HT) by enterochromaffin (EC) cells plays a key role in the emetic reflex during RV infection resulting in activation of vagal afferent nerves connected to nucleus of the solitary tract (NTS) and area postrema in the brain stem, structures associated with nausea and vomiting. Our experiments revealed that RV can infect and replicate in human EC tumor cells ex vivo and in vitro and are localized to both EC cells and infected enterocytes in the close vicinity of EC cells in the jejunum of infected mice. Purified NSP4, but not purified virus particles, evoked release of 5-HT within 60 minutes and increased the intracellular Ca(2+) concentration in a human midgut carcinoid EC cell line (GOT1) and ex vivo in human primary carcinoid EC cells concomitant with the release of 5-HT. Furthermore, NSP4 stimulated a modest production of inositol 1,4,5-triphosphate (IP(3)), but not of cAMP. RV infection in mice induced Fos expression in the NTS, as seen in animals which vomit after administration of chemotherapeutic drugs. The demonstration that RV can stimulate EC cells leads us to propose that RV disease includes participation of 5-HT, EC cells, the enteric nervous system and activation of vagal afferent nerves to brain structures associated with nausea and vomiting. This hypothesis is supported by treating vomiting in children with acute gastroenteritis with 5-HT(3) receptor antagonists.
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| 2. |
- Hagbom, Marie, et al.
(author)
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Towards a human rotavirus disease model
- 2012
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In: Current Opinion in Virology. - : Elsevier BV. - 1879-6257. ; 2:4, s. 408-418
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Journal article (peer-reviewed)abstract
- While the clinical importance of human rotavirus (RV) disease is well recognized and potent vaccines have been developed, our understanding of how human RV causes diarrhoea, vomiting and death remains unresolved. The fact that oral rehydration corrects electrolyte and water loss, indicates that enterocytes in the small intestine have a functional sodium-glucose co-transporter. Moreover, RV infection delays gastric emptying and loperamide appears to attenuate RV diarrhoea, thereby suggesting activation of the enteric nervous system. Serotonin (5-HT) receptor antagonists attenuate vomiting in young children with gastroenteritis while zinc and enkephalinase inhibitors attenuate RV-induced diarrhoea. In this review we discuss clinical symptoms, pathology, histology and treatment practices for human RV infections and compile the data into a simplified disease model.
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| 3. |
- Hammarstrand, Lars, 1979, et al.
(author)
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Adaptive Radar Sensor Model for Tracking Structured Extended Objects
- 2012
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In: IEEE Transactions on Aerospace and Electronic Systems. - 1557-9603 .- 0018-9251. ; 48:3, s. 1975 - 1995
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Journal article (peer-reviewed)abstract
- We propose a tracking framework jointly estimating the position of a single extended object and the set of radar reflectors that it contains. The reflectors are assumed to lie on a line structure, but the number of reflectors and their positions on the line are unknown. Additionally, we incorporate an accurate radar sensor model considering the resolution capabilities of the sensor. The evaluation of the framework on radar measurements shows promising results.
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| 4. |
- Jakobsen, Stig S., et al.
(author)
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Failure of total hip implants : metals and metal release in 52 cases
- 2014
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In: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 71:6, s. 319-325
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Journal article (peer-reviewed)abstract
- BackgroundThe pathogenesis of total joint replacement failure is multifactorial. One hypothesis suggests that corrosion and wear of alloys result in metal ion release, which may then cause sensitization and even implant failure, owing to the acquired immune reactivity. ObjectivesTo assess cobalt, nickel and chromium(VI) release from, and the metal composition of, failed metal-on-ethylene total hip replacements. Materials/methodsImplant components from 52 revision cases were evaluated with spot tests for free nickel, cobalt, and chromium (VI) ions. Implant composition was determined with X-ray fluorescence spectroscopy, and information on the reason for revision and complications in relation to surgery was collected from the medical charts when possible (72%). For 10 implants, corrosion was further characterized with scanning electron microscopy. ResultsWe detected cobalt release from three of 38 removed femoral heads and from one of 24 femoral stems. Nickel release was detected from one of 24 femoral stems. No chromium(VI) release was detected. ConclusionsWe found that cobalt and nickel were released from some failed total hip arthroplasties, and corrosion was frequently observed. Metal ions and particles corroded from metal-on-polyethylene may play a role in the complex aetiopathology of implant failure.
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| 5. |
- Julander, Anneli, et al.
(author)
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Formal recycling of e-waste leads to increased exposure to toxic metals : An occupational exposure study from Sweden
- 2014
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In: Environment International. - : Elsevier BV. - 0160-4120 .- 1873-6750. ; 73, s. 243-251
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Journal article (peer-reviewed)abstract
- Electrical and electronic waste (e-waste) contains multiple toxic metals. However, there is currently a lack of exposure data for metals on workers in formal recycling plants. The objective of this study was to evaluate workers' exposure to metals, using biomarkers of exposure in combination with monitoring of personal air exposure. We assessed exposure to 20 potentially toxic metals among 55 recycling workers and 10 office workers at three formal e-waste recycling plants in Sweden. Workers at two of the plants were followed-up after 6 months. We collected the inhalable fraction and OFC (37-mm) fraction of particles, using personal samplers, as well as spot samples of blood and urine. We measured metal concentrations in whole blood, plasma, urine, and air filters using inductively coupled plasma-mass spectrometry following acid digestion. The air sampling indicated greater airborne exposure, 10 to 30 times higher, to most metals among the recycling workers handling e-waste than among the office workers. The exposure biomarkers showed significantly higher concentrations of chromium, cobalt, indium, lead, and mercury in blood, urine, and/or plasma of the recycling workers, compared with the office workers. Concentrations of antimony, indium, lead, mercury, and vanadium showed close to linear associations between the inhalable particle fraction and blood, plasma, or urine. In conclusion, our study of formal waste recycling shows that workers performing recycling tasks are exposed to multiple toxic metals.
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| 6. |
- Lundgren, Lennart, et al.
(author)
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Do insulation products of man-made vitreous fibres still cause skin discomfort?
- 2014
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In: Contact Dermatitis. - : Wiley. - 0105-1873 .- 1600-0536. ; 70:6, s. 351-360
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Journal article (peer-reviewed)abstract
- Background. Man-made vitreous fibres (MMVFs) are used in products for insulation and as reinforcement in materials. Contamination of the skin may arise through direct or indirect contact, and from the deposition of airborne fibres. The scientific basis regarding the effects on skin of MMVFs dates from 1970-1980. Objectives. To investigate whether currently used insulation MMVF products still cause skin discomfort. Methods. Focus group interviews and structured interviews were performed among workers engaged in insulation tasks and among do-it-yourself consumers with a recent experience of MMVF products. Results. A majority of interviewees experienced skin discomfort when handling MMVF products. Complaints caused by traditional (yellow) glass fibre products were more severe than those caused by products of rock or slag wool fibres. The wrists, forearms, neck and face were the locations where the skin was most affected. The situations causing problems varied between occupational tasks, but working with the hands over the head or in narrow spaces were described as the worst situations. Building construction apprentices performed insulation tasks more often than senior workers. Conclusions. MMVF insulation products do still cause skin discomfort. Updated knowledge about people's experiences of work with such products should influence legislation.
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| 7. |
- Lundgren, Malin, 1979, et al.
(author)
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A CPHD Filter for Tracking With Spawning Models
- 2013
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In: IEEE Journal on Selected Topics in Signal Processing. - 1941-0484 .- 1932-4553. ; 7:3, s. 496-507
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Journal article (peer-reviewed)abstract
- In some applications of multi-target tracking, appearing targets are suitably modeled as spawning from existing targets. However, in the original formulation of the cardinalized probability hypothesis density (CPHD) filter, this type of model is not supported; instead appearing targets are modeled by spontaneous birth only. In this paper we derive the necessary equations for a CPHD filter for the case when the process model also includes target spawning. For this generalized filter, the cardinality prediction formula might become computationally intractable for general spawning models. However, when the cardinality distribution of the spawning targets is either Bernoulli or Poisson, we derive expressions that are practical and computationally efficient. Simulations show that the proposed filter responds faster to a change in target number due to spawned targets than the original CPHD filter. In addition, the performance of the filter, considering the optimal subpattern assignment (OSPA), is improved when having an explicit spawning model.
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| 8. |
- Lundgren, Malin, 1979, et al.
(author)
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A CPHD filter for tracking with spawning models - including a FISST based derivation
- 2013
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Reports (other academic/artistic)abstract
- In some applications of multi-target tracking, appearing targets are suitably modeled as spawning from existing targets. However, in the original formulation of the cardinalized probability hypothesis density (CPHD) filter, this type of model is not supported; instead appearing targets are modeled by spontaneous birth only.In this paper we derive the necessary equations for a CPHD filter for the case when the process model also includes target spawning. For this generalized filter, the cardinality prediction formula might become computationally intractable for general spawning models. However, when the cardinality distribution of the spawning targets is either Bernoulli or Poisson, we derive expressions that are practical and computationally efficient. Simulations show that the proposed filter responds faster to a change in target number due to spawned targets than the original CPHD filter. In addition, the performance of the filter, considering the optimal subpattern assignment (OSPA), is improved when having an explicit spawning model.
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| 9. |
- Lundgren, Malin, 1979, et al.
(author)
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Vehicle self-localization using off-the-shelf sensors and a detailed map
- 2014
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In: IEEE Intelligent Vehicles Symposium, Proceedings. - 9781479936380 ; , s. 522-528
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Conference paper (peer-reviewed)abstract
- In the research on autonomous vehicles, self-localization is an important problem to solve. In this paper we present a localization algorithm based on a map and a set of off-the-shelf sensors, with the purpose of evaluating this low-cost solution with respect to localization performance. The used test vehicle is equipped with a Global Positioning System receiver, a gyroscope, wheel speed sensors, a camera providing information about lane markings, and a radar detecting landmarks along the road. Evaluation shows that the localization result is within or close to the requirements for autonomous driving when lane markers and good radar landmarks are present. However, it also indicates that the solution is not robust enough to handle situations when one of these information sources is absent.
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| 10. |
- Lundgren, Ove, 1937, et al.
(author)
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Intestinal Epithelial Stem/Progenitor Cells Are Controlled by Mucosal Afferent Nerves
- 2011
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 6:2, s. 16295-
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Journal article (peer-reviewed)abstract
- Background: The maintenance of the intestinal epithelium is of great importance for the survival of the organism. A possible nervous control of epithelial cell renewal was studied in rats and mice. Methods: Mucosal afferent nerves were stimulated by exposing the intestinal mucosa to capsaicin (1.6 mM), which stimulates intestinal external axons. Epithelial cell renewal was investigated in the jejunum by measuring intestinal thymidine kinase (TK) activity, intestinal H-3-thymidine incorporation into DNA, and the number of crypt cells labeled with BrdU. The influence of the external gut innervation was minimized by severing the periarterial nerves. Principal Findings: Luminal capsaicin increased all the studied variables, an effect nervously mediated to judge from inhibitory effects on TK activity or H-3-thymidine incorporation into DNA by exposing the mucosa to lidocaine (a local anesthetic) or by giving four different neurotransmitter receptor antagonists i.v. (muscarinic, nicotinic, neurokinin1 (NK1) or calcitonin gene related peptide (CGRP) receptors). After degeneration of the intestinal external nerves capsaicin did not increase TK activity, suggesting the involvement of an axon reflex. Intra-arterial infusion of Substance P (SP) or CGRP increased intestinal TK activity, a response abolished by muscarinic receptor blockade. Immunohistochemistry suggested presence of M3 and M5 muscarinic receptors on the intestinal stem/progenitor cells. We propose that the stem/progenitor cells are controlled by cholinergic nerves, which, in turn, are influenced by mucosal afferent neuron(s) releasing acetylcholine and/or SP and/or CGRP. In mice lacking the capsaicin receptor, thymidine incorporation into DNA and number of crypt cells labeled with BrdU was lower than in wild type animals suggesting that nerves are important also in the absence of luminal capsaicin, a conclusion also supported by the observation that atropine lowered thymidine incorporation into DNA by 60% in control rat segments. Conclusion: Enteric nerves are of importance in maintaining the intestinal epithelial barrier.
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| 11. |
- Lundgren, Tobias, et al.
(author)
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The Bull's-Eye Values Survey : A Psychometric Evaluation
- 2012
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In: Cognitive and Behavioral Practice. - : Elsevier BV. - 1077-7229 .- 1878-187X. ; 19:4, s. 518-526
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Journal article (peer-reviewed)abstract
- Purpose: Two studies were conducted to develop and evaluate an instrument attempting to identify and measure personal values, values attainment and believability in thoughts functioning as obstacles in living a valued life. Study one describes a content validity approach to the construction and preliminary validation of the Bull’s Eye Values Survey (BEVS), using a sample of institutionalized patients suffering from Epilepsy. Study Two investigated the psychometric properties of the BEVS with a sample of Swedish university students. Results indicate that the BEVS is sensitive to treatment effects and can differentiate between clients who receive values based interventions and those that do not. The BEVS subscales and total score appear to measure an independent dimension of psychological functioning that is negatively correlated with measures of depression, anxiety and stress and positively correlated with a measure of psychological flexibility. The BEVS also exhibits acceptable temporal stability and internal consistency. The study provides preliminary support for the BEVS as both a research and clinical tool for measuring values, valued action discrepancies and barriers to value based living.
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| 12. |
- Palmqvist, Py, et al.
(author)
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Interleukin-4 and interleukin-13 inhibit the expression of leukemia inhibitory factor and interleukin-11 in fibroblasts.
- 2012
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In: Molecular immunology. - : Elsevier BV. - 1872-9142 .- 0161-5890. ; 49:4, s. 601-10
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Journal article (peer-reviewed)abstract
- Cytokines produced by inflammatory or resident mesenchymal cells play important modulatory roles in the pathogenesis of inflammation induced bone loss. In the present study, the effects of IL-4 and IL-13 on the expression of three osteotropic cytokines in the IL-6 family expressed in human gingival fibroblasts were studied. IL-4Rα and IL-13Rα1 mRNA were constitutively expressed in human gingival fibroblasts. The inflammatory cytokines IL-1β and TNF-α increased expression of IL-6, LIF, and IL-11 mRNA and protein in the gingival fibroblasts. Addition of IL-4 or IL-13 had no effect on IL-6 expression, but significantly inhibited LIF and IL-11 mRNA and protein stimulated by IL-1β and TNF-α. No involvement of NF-κB or STAT1 was observed in the inhibition. STAT6 was phosphorylated at Y641 by treatment with IL-4 and knockdown of STAT6 with siRNA decreased the inhibition of IL-11 and LIF expression by IL-4 in IL-1β and TNF-α stimulated cells. This study suggests that activation of STAT6 by IL-4 and IL-13, through type 2 IL-4 receptors, inhibits production of IL-11 and LIF stimulated by IL-1β and TNF-α in human gingival fibroblasts. A negative modulatory role of IL-4 and IL-13 in osteotropic cytokine production could be a mechanism playing an important inhibitory role in inflammation induced periodontitis.
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| 13. |
- Thyssen, Jacob P., et al.
(author)
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Sensitivity and specificity of the nickel spot (dimethylglyoxime) test
- 2010
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In: Contact Dermatitis. - 0105-1873 .- 1600-0536. ; 62:5, s. 279-288
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Journal article (peer-reviewed)abstract
- Objectives: To evaluate the sensitivity and specificity of the DMG test. Methods: DMG spot testing, chemical analysis according to the EN 1811 reference method, and X-ray fluorescence spectroscopy (XRF) were performed concomitantly on 96 metallic components from earrings recently purchased in San Francisco. Results: The sensitivity of the DMG test was 59.3% and the specificity was 97.5% based on DMG-test results and nickel release concentrations determined by the EN 1811 reference method. Conclusions: The DMG test has a high specificity but a modest sensitivity. It may serve well for screening purposes. Past exposure studies may have underestimated nickel release from consumer items.
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