| 1. |
- Ledin, Johan, et al.
(författare)
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Enzymatically active N-deacetylase/N-sulfotransferase-2 is present in liver but does not contribute to heparan sulfate N-sulfation
- 2006
-
Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 281:47, s. 35727-35734
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Tidskriftsartikel (refereegranskat)abstract
- Heparan sulfate (HS) proteoglycans influence embryonic development through interactions with growth factors and morphogens. The interactions depend on HS structure, which is largely determined during biosynthesis by Golgi enzymes. NDST ( glucosaminyl N-deacetylase/N-sulfotransferase), responsible for HSN-sulfation, is a key enzyme directing further modifications including O-sulfation. To elucidate the roles of the different NDST isoforms in HS biosynthesis, we took advantage of mice with targeted mutations in NDST1 and NDST2 and used liver as our model organ. Of the four NDST isoforms, only NDST1 and NDST2 transcripts were shown to be expressed in control liver. The absence of NDST1 or NDST2 in the knock-out mice did not affect transcript levels of other NDST isoforms or other HS modification enzymes. Although the sulfation level of HS synthesized in NDST1(-/-) mice was drastically lowered, liver HS from wild-type mice, from NDST1(-/-), NDST2(-/-), and NDST1(-/-), NDST2(-/-) mice all had the same structure despite greatly reduced NDST enzyme activity (30% of control levels in NDST1(-/-) NDST2(-/-) embryonic day 18.5 embryos). Enzymatically active NDST2 was shown to be present in similar amounts in wild-type, NDST1(-/-), and NDST1(-/-) embryonic day 18.5 liver. Despite the substantial contribution of NDST2 to total NDST enzyme activity in embryonic day 18.5 liver (approximate to 40%), its presence did not appear to affect HS structure as long as NDST1 was also present. In NDST1(-/-) embryonic day 18.5 liver, in contrast, NDST2 was responsible for N-sulfation of the low sulfated HS. A tentative model to explain these results is presented.
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| 2. |
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| 3. |
- Presto, Jenny, et al.
(författare)
-
Heparan sulfate biosynthesis enzymes EXT1 and EXT2 affect NDST1 expression and heparan sulfate sulfation
- 2008
-
Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424 .- 1091-6490. ; 105:12, s. 4751-4756
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Tidskriftsartikel (refereegranskat)abstract
- Heparan sulfate (HS) proteoglycans influence embryonic development and adult physiology through interactions with protein ligands. The interactions depend on HS structure, which is determined largely during biosynthesis by Golgi enzymes. How biosynthesis is regulated is more or less unknown. During polymerization of the HS chain, carried out by a complex of the exostosin proteins EXT1 and EXT2, the first modification enzyme, glucosaminyl N-deacetylase/N-sulfotransferase (NDST), introduces N-sulfate groups into the growing polymer. Unexpectedly, we found that the level of expression of EXT1 and EXT2 affected the amount of NDST1 present in the cell, which, in turn, greatly influenced HS structure. Whereas overexpression of EXT2 in HEK 293 cells enhanced NDST1 expression, increased NDST1 N-glycosylation, and resulted in elevated HS sulfation, overexpression of EXT1 had opposite effects. Accordingly, heart tissue from transgenic mice overexpressing EXT2 showed increased NDST activity. Immunoprecipitaion experiments suggested an interaction between EXT2 and NDST1. We speculate that NDST1 competes with EXT1 for binding to EXT2. Increased NDST activity in fibroblasts with a gene trap mutation in EXT1 supports this notion. These results support a model in which the enzymes of HS biosynthesis form a complex, or a GAGosome.
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| 4. |
- Aquilonius, Elisabeth, et al.
(författare)
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Forskarservice - en utredning om Bibliotek och ITs verksamhet riktad mot högskolans forskning
- 2008
-
Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Syftet med utredningen är att skapa förutsättningar för att bättre kunna möta forskningens behov och bidra till att effektivisera forskarnas arbete genom stöd till informationsförsörjning och IT. Den organisationsövergripande dialogen, kartläggningen, de förslag och pilotprojekt som arbetats med inom utredningen, och som föreligger här är tänkt att kunna fungera som såväl beslutsunderlag som idébank till BITs framtida service för högskolans forskare.
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| 5. |
- Arnason, Ulfur, et al.
(författare)
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Mammalian mitogenomic relationships and the root of the eutherian tree.
- 2002
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Ingår i: Proceedings of the National Academy of Sciences. - : Proceedings of the National Academy of Sciences. - 1091-6490 .- 0027-8424. ; 99:12, s. 8151-8156
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Tidskriftsartikel (refereegranskat)abstract
- The strict orthology of mitochondrial (mt) coding sequences has promoted their use in phylogenetic analyses at different levels. Here we present the results of a mitogenomic study (i.e., analysis based on the set of protein-coding genes from complete mt genomes) of 60 mammalian species. This number includes 11 new mt genomes. The sampling comprises all but one of the traditional eutherian orders. The previously unrepresented order Dermoptera (flying lemurs) fell within Primates as the sister group of Anthropoidea, making Primates paraphyletic. This relationship was strongly supported. Lipotyphla ("insectivores") split into three distinct lineages: Erinaceomorpha, Tenrecomorpha, and Soricomorpha. Erinaceomorpha was the basal eutherian lineage. Sirenia (dugong) and Macroscelidea (elephant shrew) fell within the African clade. Pholidota (pangolin) joined the Cetferungulata as the sister group of Carnivora. The analyses identified monophyletic Pinnipedia with Otariidae (sea lions, fur seals) and Odobenidae (walruses) as sister groups to the exclusion of Phocidae (true seals).
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| 6. |
- Brännström, Kristoffer, et al.
(författare)
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The Schistosoma mansoni protein Sm16/SmSLP/SmSPO-1 assembles into a nine-subunit oligomer with potential To inhibit Toll-like receptor signaling
- 2009
-
Ingår i: Infection and Immunity. - 0019-9567 .- 1098-5522. ; 77:3, s. 1144-1154
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Tidskriftsartikel (refereegranskat)abstract
- The Sm16/SmSLP/SmSPO-1 (Sm16) protein is secreted by the parasite Schistosoma mansoni during skin penetration and has been ascribed immunosuppressive activities. Here we describe the strategy behind the design of a modified Sm16 protein with a decreased aggregation propensity, thus facilitating the expression and purification of an Sm16 protein that is soluble in physiological buffers. The Stokes radii and sedimentation coefficients of recombinant and native proteins indicate that Sm16 is an approximately nine-subunit oligomer. Analysis of truncated Sm16 derivatives showed that both oligomerization and binding to the plasma membrane of human cells depend on multiple C-terminal regions. For analysis of immunomodulatory activities, Sm16 was expressed in Pichia pastoris to facilitate the preparation of a pyrogen/endotoxin-free purified protein. Recombinant Sm16 was found to have no effect on T-lymphocyte activation, cell proliferation, or the basal level of cytokine production by whole human blood or monocytic cells. However, Sm16 exerts potent inhibition of the cytokine response to the Toll-like receptor (TLR) ligands lipopolysaccharide (LPS) and poly(I:C) while being less efficient at inhibiting the response to the TLR ligand peptidoglycan or a synthetic lipopeptide. Since Sm16 specifically inhibits the degradation of the IRAK1 signaling protein in LPS-stimulated monocytes, our findings indicate that inhibition is exerted proximal to the TLR complex.
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| 7. |
- Busse, Marta, et al.
(författare)
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Contribution of EXT1, EXT2, and EXTL3 to heparan sulfate chain elongation
- 2007
-
Ingår i: Journal of Biological Chemistry. - 0021-9258 .- 1083-351X. ; 282:45, s. 32802-32810
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Tidskriftsartikel (refereegranskat)abstract
- The exostosin (EXT) family of genes encodes glycosyltransferases involved in heparan sulfate biosynthesis. Five human members of this family have been cloned to date: EXT1, EXT2, EXTL1, EXTL2, and EXTL3. EXT1 and EXT2 are believed to form a Golgi-located hetero-oligomeric complex that catalyzes the chain elongation step in heparan sulfate biosynthesis, whereas the EXTL proteins exhibit overlapping glycosyl-transferase activities in vitro, so that it is not apparent what reactions they catalyze in vivo. We used gene-silencing strategies to investigate the roles of EXT1, EXT2, and EXTL3 in heparan sulfate chain elongation. Small interfering RNAs (siRNAs) directed against the human EXT1, EXT2, or EXTL3 mRNAs were introduced into human embryonic kidney 293 cells. Compared with cells transfected with control siRNA, those transfected with EXT1 or EXT2 siRNA synthesized shorter heparan sulfate chains, and those transfected with EXTL3 siRNA synthesized longer chains. We also generated human cell lines overexpressing the EXT proteins. Overexpression of EXT1 resulted in increased HS chain length, which was even more pronounced in cells coexpressing EXT2, whereas overexpression of EXT2 alone had no detectable effect on heparan sulfate chain elongation. Mutations in either EXT1 or EXT2 are associated with hereditary multiple exostoses, a human disorder characterized by the formation of cartilage-capped bony outgrowths at the epiphyseal growth plates. To further investigate the role of EXT2, we generated human cell lines overexpressing mutant EXT2. One of the mutations, EXT2-Y419X, resulted in a truncated protein. Interestingly, the capacity of wild type EXT2 to enhance HS chain length together with EXT1 was not shared by the EXT2-Y419X mutant.
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| 8. |
- EL Hiar, Raida, et al.
(författare)
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Enteroviral Central Nervous System Infections in Children of the Region of Monastir, Tunisia : Diagnosis, Laboratory Findings of Cerebrospinal Fluid and Clinical Manifestations
- 2012
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Ingår i: Indian Journal of Virology. - : Springer Science and Business Media LLC. - 0970-2822 .- 0974-0120. ; 23:3, s. 294-302
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Tidskriftsartikel (refereegranskat)abstract
- Human enteroviruses (HEV) are one of the major causes of central nervous system (CNS) infections in pediatrics. A prospective study was conducted to assess the epidemiological, clinical, and laboratory characteristics of enterovirus (EV) infections of the CNS in children under 15-years-old, suspected of having viral CNS infections and admitted to the Pediatric Department of Monastir University Hospital, Tunisia. Enteroviral RNA was detected by 5' NCR nested RT-PCR assay in 33 % (20 out of 60) of cerebrospinal fluid specimens, whereas only six samples (10 %) were EV positive in cell culture. EV-positive patients were clustered according to their clinical manifestations, predominantly diagnosed as aseptic meningitis (65 %) and meningoencephalitis (20 %). Fever, headache, vomiting, and neck stiffness were the most pronounced symptoms. Pleocytosis with the predominance of lymphocytes was observed in 60 % of EV positive specimens. Although patients suffering from EV infections were encountered throughout the year, most occurred during spring and summer months. Using VP1-2A nested RT-PCR and sequence analysis, three of the 20 positive HEV were identified as Echovirus (E)-9. This is the first report of a cluster of aseptic meningitis cases caused by E-9 in Monastir.
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| 9. |
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| 10. |
- Graziano, Maria, et al.
(författare)
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Gesture production and speech fluency in competent speakers and language learners
- 2013
-
Ingår i: [Host publication title missing].
-
Konferensbidrag (refereegranskat)abstract
- It is often assumed that a main function of gestures is to compensate for expressive difficulties. This predicts that gestures should mainly occur with disfluent speech. However, surprisingly little is known about the relationship between gestures and fluent vs. disfluent speech. This study investigates the putative ompensatory role of gesture by examining competent speakers’ and language learners’ gestural production in fluent vs. non-fluent speech. Results show that both competent and less competent speakers predominantly produce gestures during fluent stretches of speech; ongoing gestures during disfluencies are suspended. In all groups, the few gestures that are completed during disfluencies are both referential and pragmatic. The findings strongly suggest that when speech stops, so do gestures, thus supporting the view of speech and gesture as an integrated system.
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| 11. |
- Graziano, Maria, et al.
(författare)
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Providing evidence for a well-worn stereotype : Italians and Swedes do gesture differently
- 2024
-
Ingår i: Frontiers in Communication. - 2297-900X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Across cultures and languages spontaneous speech is often accompanied bygestures. It is a popular belief that people in Italy gesture more than peoplein Northern Europe, such as in Sweden. Despite this general assumption fewstudies empirically investigate cultural differences in gesture frequency andgesture function under similar circumstances. This study compares the spokenand gestural behaviours of Italian and Swedish speakers, assumed to representgesture-rich vs. gesture-sparse cultures. We examine the groups’ gesturalbehaviour for frequency, and in terms of possible differences in rhetorical styleprobing the distribution of gestural functions (referential vs. pragmatic) acrossnarrative levels (narrative, metanarrative, and paranarrative). The results showthat (1) Italians overall do gesture more than Swedes; (2) Italians produce morepragmatic gestures than Swedes who produce more referential gestures; (3)both groups show sensitivity to narrative level: referential gestures mainly occurwith narrative clauses, and pragmatic gestures with meta- and paranarrativeclauses. However, the overall group preferences for different functions still leadto different styles. These findings indicate that the two groups differ in gesturerate and, more interestingly, in rhetorical styles, one focused on events andactions in speech and gesture (Swedish), the other alternating between eventsin speech and gesture, and the highlighting of the presentation of new pieces ofinformation in gesture only (Italian). We propose that the findings suggest that thetwo groups conceptualise narrative production in different ways reflected in twodifferent rhetorical styles revealed by gesture production more than by speech.
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| 12. |
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| 13. |
- Graziano, Maria, et al.
(författare)
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When speech stops, gesture stops : Evidence from crosslinguistic and developmental comparisons
- 2018
-
Ingår i: Frontiers in Psychology. - : Frontiers Media SA. - 1664-1078. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- There is plenty of evidence that speech and gesture form a tightly integrated system, as reflected in parallelisms in language production, comprehension, and development (Kendon, 2004; McNeill, 1992). Yet, it is a common assumption that speakers use gestures to compensate for their expressive difficulties, a notion found in developmental studies of both first and second language acquisition, and in some theoretical proposals concerning the gesture-speech relationship. If gestures are compensatory, they should mainly occur in disfluent stretches of speech. However, the evidence is sparse and conflicting. This study tests the putative compensatory role of gestures by comparing the gestural behaviour in fluent vs. disfluent stretches of narratives by competent speakers in two languages (Dutch and Italian), and by language learners (children and adult L2 learners). The results reveal that (1) in all groups speakers overwhelmingly produce gestures during fluent speech and only rarely during disfluencies. However, L2 learners are significantly more likely to gesture in disfluency than the other groups; (2) in all groups any gestures performed during disfluencies tend to be suspended; (3) in all groups the rare gestures completed in disfluencies have both referential and pragmatic functions. Overall, the data strongly suggest that when speech stops, so does gesture. The findings constitute an important challenge to both gesture and language acquisition theories assuming a mainly (lexical) compensatory role for (referential) gestures. Instead, the results provide strong support for the notion that speech and gestures form an integrated system.
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| 14. |
- Gullberg, Elisabet, et al.
(författare)
-
Yersinia pseudotuberculosis induces transcytosis of nanoparticles across human intestinal villus epithelium via invasin-dependent macropinocytosis
- 2008
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Ingår i: Laboratory investigation; a journal of technical methods and pathology. - New York, USA : Elsevier BV. - 1530-0307 .- 0023-6837. ; 88:11, s. 1215-26
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Tidskriftsartikel (refereegranskat)abstract
- Crohn's disease is characterized by a defect in intestinal barrier function, where bacteria are considered the most important inflammation-driving factor. Enteric bacteria, including E. coli and Yersinia spp, affect tight junctions in enterocytes, but little is known about bacterial effects on the transcellular pathway. Our objective was to study the short-term effects of Y. pseudotuberculosis on uptake of nanoparticles across human villus epithelium. Monolayers of human colon epithelium-derived Caco-2 cells and biopsies of normal human ileum were studied after 2 h exposure to Y. pseudotuberculosis expressing (inv+) or lacking (inv-) the bacterial adhesion molecule, invasin. Transepithelial transport of fluorescent nanoparticles (markers of transcytosis) was quantified by flow cytometry, and mechanisms explored by using inhibitors of endocytosis. Epithelial expressions of beta1-integrin and particle uptake pathways were studied by confocal microscopy. The paracellular pathway was assessed by electrical resistance (TER), mannitol flux, and expression of tight junction proteins occludin and caludin-4 by confocal microscopy. Inv+ Y. pseudotuberculosis adhered to the apical surface of epithelial cells and induced transcytosis of exogenous nanoparticles across Caco-2 monolayers (30-fold increase, P<0.01) and ileal mucosa (268+/-47% of control; P<0.01), whereas inv bacteria had no effect on transcytosis. The transcytosis was concentration-, particle size- and temperature-dependent, and possibly mediated via macropinocytosis. Y. pseudotuberculosis also induced apical expression of beta1-integrin on epithelial cells. A slight drop in TER was seen after exposure to inv+ Y. pseudotuberculosis, whereas mannitol flux and tight junction protein expression was unchanged. In summary, Y. pseudotuberculosis induced apical expression of beta1-integrin and stimulated uptake of nanoparticles via invasin-dependent transcytosis in human intestinal epithelium. Our findings suggest that bacterial factors may initiate transcytosis of luminal exogenous particles across human ileal mucosa, thus presenting a novel mechanism of intestinal barrier dysfunction.
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| 15. |
- Gullberg, Maria, et al.
(författare)
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A single coxsackievirus B2 capsid residue controls cytolysis and apoptosis in rhabdomyosarcoma cells.
- 2010
-
Ingår i: Journal of Virology. - 0022-538X .- 1098-5514. ; 84:12, s. 5868-5879
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Tidskriftsartikel (refereegranskat)abstract
- Coxsackievirus B2 (CVB2), one of six human pathogens of the group B coxsackieviruses within the enterovirus genus of Picornaviridae, causes a wide spectrum of human diseases ranging from mild upper respiratory illnesses to myocarditis and meningitis. The CVB2 prototype strain Ohio-1 (CVB2O) was originally isolated from a patient with summer grippe in the 1950s. Later on, CVB2O was adapted to cytolytic replication in rhabdomyosarcoma (RD) cells. Here, we present analyses of the correlation between the adaptive mutations of this RD variant and the cytolytic infection in RD cells. Using reverse genetics, we identified a single amino acid change within the exposed region of the VP1 protein (glutamine to lysine at position 164) as the determinant for the acquired cytolytic trait. Moreover, this cytolytic virus induced apoptosis, including caspase activation and DNA degradation, in RD cells. These findings contribute to our understanding of the host cell adaptation process of CVB2O and provide a valuable tool for further studies of virus-host interactions.
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| 16. |
- Gullberg, Maria, et al.
(författare)
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Characterization of a putative ancestor of coxsackievirus B5.
- 2010
-
Ingår i: Journal of Virology. - 0022-538X .- 1098-5514. ; 84, s. 9695-9708
-
Tidskriftsartikel (refereegranskat)abstract
- Like other RNA viruses, coxsackievirus B5 (CVB5) exists as circulating heterogeneous populations of genetic variants. In this study, we present the reconstruction and characterization of a probable ancestral virion of CVB5. Phylogenetic analyses based on capsid protein encoding regions (the VP1 gene of 41 clinical isolates and the entire P1 region of eight clinical isolates) of CVB5 revealed two major co-circulating lineages. Ancestral capsid sequences were inferred from sequences of these contemporary CVB5 isolates using maximum likelihood methods. By using Bayesian phylodynamic analysis, the inferred VP1 ancestral sequence was dated back to 1854 (1807-1898). In order to study the properties of the putative ancestral capsid, the entire ancestral P1 sequence was synthesized de novo and inserted into the replicative backbone of an infectious CVB5 cDNA clone. Characterization of the recombinant virus in cell culture showed that fully functional infectious virus particles were assembled and that these viruses displayed properties similar to those of modern isolates, in terms of receptor preferences, plaque phenotype, growth characteristics and cell tropism. This is the first report describing resurrection and characterization of a picornavirus with a putative ancestral capsid. Our approach, including phylogenetics-based reconstruction of viral predecessors, could serve as a starting point for experimental studies of viral evolution and might also provide an alternative strategy in the development of vaccines.
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| 17. |
- Gullberg, Maria, et al.
(författare)
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DDC på Malmö högskolas bibliotek
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Rapport om hur en övergång till DDC bokuppställning skulle kunna ske på Malmö högskolas bibliotek. Förslag på ny hylluppställning och hur en transformation kan ske stegvist.
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| 18. |
- Gullberg, Maria, et al.
(författare)
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Forskarservice - en utredning vid Malmö University
- 2008
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Ingår i: DF-revy. - : Danmarks Forskningsbiblioteksforening. - 0106-0503 .- 1901-1903. ; 31:8, s. 18-20
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- I mars 2008 presenterades en utredning om Bibliotek och ITs forskarservice på Malmö University. Syftet med utredningen var dels att sammanställa en nulägesbeskrivning av forskarservicen och dels att se vilka utmaningar som ligger i framtiden genom att i nära kontakt med forskarna undersöka i vilken riktning forskarservicen kan utvecklas.
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| 19. |
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| 20. |
- Günter, Katerina Pia, 1989-
(författare)
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Figuring Worlds; Imagining Paths : A Feminist Exploration of Identities in Higher Education Biology
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Higher education biology is a natural science discipline that is numerically female biased on undergraduate level across most international contexts. In Sweden, Germany, and the UK, for example, more than 60% of all undergraduate students are women. However, equally prominent in these European contexts and beyond is the progressive decrease in the percentage of women along the academic career ladder, resulting in fewer than 30% of women among full professors in biology. This numerical decline contradicts unproblematised understandings of biology practices as gender-neutral, where biology as a female-coded and “soft” natural science discipline is perceived as free from gendered processes of in- and exclusion. As pointed out by feminist critics of science and science education researchers, gender-neutral discourses hide gendered processes; they unmark, neutralize, and normalize masculinity in natural science practices. Gendered norms in relation to issues of identity and participation in higher education science have been addressed rather extensively in male-dominated natural science disciplines such as physics. However, only a few studies focus these lenses on higher education biology. In this thesis, I explore how university students and teachers negotiate identities, make meaning of emotions, and figure worlds of higher education biology. As a trained biologist and a becoming gender scholar and science educator, I explore biology cultures from in- and outside perspectives. Working from within and between disciplines also provides me with theoretical and methodological tools to understand processes of enculturation in higher education biology, building on an eclectic theoretical framework, combining feminist, social constructivist, and cultural perspectives. I analyse students’ study motivation texts and teachers’ teaching statements from a Swedish context, as well as interviews with university biology students from three European universities in Sweden, Germany, and the UK. Across the four papers included in this thesis, narrow masculine norms of science, and particularly research, emerge in students’ and teachers’ identity work. These norms are challenged through alternative and broader imaginaries of biology practice and interpretations of participation within. On the one hand, recognizing broader identities has the potential to widen the practice of higher education biology. On the other hand, students negotiating alternatives to the norm risk not being recognized in interactions with research-focused teachers and hence being hindered in developing a sense of belonging to biology communities. Female students showed a tendency to imagine participation in broader ways, and the clash of this with the normative cultural imaginaries within higher education biology risks contributing to the progressive decrease of the percentage of women in biology at universities. Taken together, this thesis provides further evidence for how higher education biology is far from a gender-neutral natural science discipline. While hegemonic and masculine norms of doing science and research are visible in university biology students’ and teachers’ identity work, alternative imaginaries provide possibilities for change towards a more diverse field of biology.
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| 21. |
- Israelsson, Stina, et al.
(författare)
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Cytolytic replication of echoviruses in colon cancer cell lines
- 2011
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Ingår i: Virology Journal. - 1743-422X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Colorectal cancer is one of the most common cancers in the world, killing nearly 50% of patients afflicted. Though progress is being made within surgery and other complementary treatments, there is still need for new and more effective treatments. Oncolytic virotherapy, meaning that a cancer is cured by viral infection, is a promising field for finding new and improved treatments. We have investigated the oncolytic potential of several low-pathogenic echoviruses with rare clinical occurrence. Echoviruses are members of the enterovirus genus within the family Picornaviridae.METHODS: Six colon cancer cell lines (CaCo-2, HT29, LoVo, SW480, SW620 and T84) were infected by the human enterovirus B species echovirus 12, 15, 17, 26 and 29, and cytopathic effects as well as viral replication efficacy were investigated. Infectivity was also tested in spheroids grown from HT29 cells.RESULTS: Echovirus 12, 17, 26 and 29 replicated efficiently in almost all cell lines and were considered highly cytolytic. The infectivity of these four viruses was further evaluated in artificial tumors (spheroids), where it was found that echovirus 12, 17 and 26 easily infected the spheroids.CONCLUSIONS: We have found that echovirus 12, 17 and 26 have potential as oncolytic agents against colon cancer, by comparing the cytolytic capacity of five low-pathogenic echoviruses in six colon cancer cell lines and in artificial tumors.
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| 22. |
- Israelsson, Stina, et al.
(författare)
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Studies of Echovirus 5 interactions with the cell surface: Heparan sulfate mediates attachment to the host cell.
- 2010
-
Ingår i: Virus Research. - : Elsevier BV. - 0168-1702 .- 1872-7492. ; 151:2, s. 170-176
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Tidskriftsartikel (refereegranskat)abstract
- Infections caused by Echovirus 5 (E5), an enterovirus of the Picornaviridae family, have been associated with fever, rashes and sporadic cases of aseptic meningitis. To elucidate the receptor usage of this virus, the significance of a previously proposed integrin binding arginine-glycine-aspartic acid (RGD) motif found in the VP3 capsid protein was investigated, as well as the capacity of E5 to interact with heparan sulfate on the cell surface. Using the prototype strain E5 Noyce (E5N), an E5N mutant where the aspartic acid of the RGD motif has been substituted to a glutamic acid and clinical E5 isolates, the RGD motif of VP3 was found to be non-essential and hence not involved in integrin receptor binding. However, E5N and clinical E5 isolates interact with heparan sulfate at the cell surface, as demonstrated by virus replication inhibition assays using heparin and heparinase III, and studies of E5 interactions at the cell surface measured by real-time PCR analysis. In conclusion, E5 utilizes heparan sulfate as a cellular receptor, but the RGD motif of VP3 is not essential for E5 infectivity.
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| 23. |
- Jonsson, Nina, et al.
(författare)
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A rapid and efficient method for studies of virus interaction at the host cell surface using enteroviruses and real-time PCR
- 2009
-
Ingår i: Virology Journal. - 1743-422X. ; 6:Article ID: 217
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Measuring virus attachment to host cells is of great importance when trying to identify novel receptors. The presence of a usable receptor is a major determinant of viral host range and cell tropism. Furthermore, identification of appropriate receptors is central for the understanding of viral pathogenesis and gives possibilities to develop antiviral drugs. Attachment is presently measured using radiolabeled and subsequently gradient purified viruses. Traditional methods are expensive and time-consuming and not all viruses are stable during a purification procedure; hence there is room for improvement. Real-time PCR (RT-PCR) has become the standard method to detect and quantify virus infections, including enteroviruses, in clinical samples. For instance, primers directed to the highly conserved 5' untranslated region (5'UTR) of the enterovirus genome enable detection of a wide spectrum of enteroviruses. Here, we evaluate the capacity of the RT-PCR technology to study enterovirus host cell interactions at the cell surface and compare this novel implementation with an established assay using radiolabeled viruses. Results: Both purified and crude viral extracts of CVB5 generated comparable results in attachment studies when analyzed with RT-PCR. In addition, receptor binding studies regarding viruses with coxsackie- nd adenovirus receptor (CAR) and/or decay accelerating factor (DAF) affinity, further demonstrated the possibility to use RT-PCR to measure virus attachment to host cells. Furthermore, the RT-PCR technology and crude viral extracts was used to study attachment with low multiplicity of infection (0.05 x 10(-4)TCID(50)/cell) and low cell numbers (250), which implies the range of potential implementations of the presented technique. Conclusion: We have implemented the well-established RT-PCR technique to measure viral attachment to host cells with high accuracy and reproducibility, at low cost and with less effort than traditional methods. Furthermore, replacing traditional methods with RT-PCR offers the opportunity to use crude virus containing extracts to investigate attachment, which could be considered as a step towards viral attachment studies in a more natural state.
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| 24. |
- Jonsson, Nina, et al.
(författare)
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Efficient replication of recombinant Enterovirus B types, carrying different P1 genes in the coxsackievirus B5 replicative backbone
- 2015
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Ingår i: Virus genes. - : Springer Science and Business Media LLC. - 0920-8569 .- 1572-994X. ; 50:3, s. 351-357
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Tidskriftsartikel (refereegranskat)abstract
- Recombination is an important feature in theevolution of the Enterovirus genus. Phylogenetic studies ofenteroviruses have revealed that the capsid genomic region(P1) is type specific, while the parts of the genome codingfor the non-structural proteins (P2–P3) are species specific.Hence, the genome may be regarded as consisting of twomodules that evolve independently. In this study, it wasinvestigated whether the non-structural coding part of thegenome in one type could support replication of a virus witha P1 region from another type of the same species. A cas-sette vector (pCas) containing a full-length cDNA copy ofcoxsackievirus B5 (CVB5) was used as a replicative back-bone. The P1 region of pCas was replaced with the corre-sponding part from coxsackievirus B3Nancy(CVB3N),coxsackievirus B6Schmitt(CVB6S), and echovirus 7Wal-lace(E7W), all members of theEnterovirus Bspecies. Thereplication efficiency after transfection with clone-derivedin vitro transcribed RNA was studied and compared withthat of pCas. All the recombinant viruses replicated with similar efficiencies and showed threshold cycle (Ct) values,tissue culture infectivity dose 50 %, and plaque-forming unittiters comparable to viruses generated from the pCas con-struct. In addition to this, a clone without the P1 region wasalso constructed, and Western Blot and immunofluorescencestaining analysis showed that the viral genome could betranslated and replicated despite the lack of the structuralprotein-coding region. To conclude, the replicative back-bone of the CVB5 cassette vector supports replication ofintraspecies constructs with P1 regions derived from othermembers of theEnterovirus Bspecies. In addition to this,the replicative backbone can be both translated and repli-cated without the presence of a P1 region.
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| 25. |
- Jonsson, Nina, et al.
(författare)
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Real-time polymerase chain reaction as a rapid and efficient alternative to estimation of picornavirus titers by tissue culture infectious dose 50% or plaque forming units
- 2009
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Ingår i: Microbiology and immunology. - : Wiley. - 0385-5600 .- 1348-0421. ; 53:3, s. 149-154
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Tidskriftsartikel (refereegranskat)abstract
- Quantification of viral infectious units is traditionally measured by methods based on forming plaques in semisolid media (PFU) or endpoint dilution of a virus-containing solution (TCID(50)), methods that are laborious, time-consuming and take on average 3-7 days to carry out. Quantitative real-time PCR is an established method to quantify nucleic acids at high accuracy and reproducibility, routinely used for virus detection and identification. In the present study, a procedure was developed using a two-step real-time PCR and the SYBR Green detection method to study whether there are correlations between TCID(50)/ml, PFU/ml and Ct values generated by real-time PCR enabling rapid and efficient calculation of titer equivalents when working with viruses in the research laboratory. In addition, an external standard with known concentrations was included using in vitro transcribed viral RNA, thus allowing the calculation of the amount of RNA copies needed for various applications (i.e. per plaque or TCID(50)).The results show that there is a correlation between the three quantification methods covering a wide range of concentration of viruses. Furthermore, a general regression line between TCID(50) and Ct values was obtained for all viruses included in the study, which enabled recording titer equivalents using real-time PCR. Finally, by including an external standard, the amount of RNA genomes generating one TCID(50) or PFU for each enterovirus serotype included was determined.
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| 26. |
- Junkala, Hannele, 1963-
(författare)
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Balansakter - kroppar, sexualiteter och det oväntade : kritiska och didaktiska perspektiv på sexualundervisning inom biologiämnet
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sexuality education (SE) involves topics that can be perceived as sensitive and private, which creates challenges for teachers. Teachers in Sweden feel uncomfortable with the subject of SE, as they lack knowledge about LGBTQ issues and experience uncertainty in handling charged discussions. Therefore, teachers need tools for teaching this subject, regarding both the content itself and the teaching methods. Aiming to facilitate inclusive SE, this thesis thus contributes to the knowledge of contemporary SE in Sweden. Two studies were conducted: the first addressing Swedish Biology textbooks in grades 7-9, and the second involving classroom observations in three different teachers’ SE teaching in grade 8. These studies were developed into four papers.Paper 1 presents a content analysis of five Swedish Biology textbooks using feminist, crip and queer perspectives. The results show that trans persons, homosexuality, bisexuality, and heterosexuality are standard content. Representations of disabilities are sparse, while intersex and asexuality are not included. In paper 2, Swedish whiteness is analysed in the textbooks and teacher interviews through the lens of critical race theory. The findings reveal that references to legislation, science, progression, ethnicity, tradition, and culture construct Swedish whiteness as a ‘happy’ place ‘here’, in contrast to less happy places elsewhere, far away ‘there’. Paper 3 concerns different tensions that arise during classroom teaching and how teachers balance these situations. Both the anti-oppressive strategies and the teaching methods focused on processes, facts, and relations are analysed. The results show that teachers can use tensions in SE to challenge prejudice and heteronormative assumptions. Also, teachers’ inclusion of students’ thoughts and worlds, even around controversial topics, creates recognition, subjectification, and meaning making for the students. Paper 4 explores how teachers handle unexpected situations in SE classrooms. The short interruptions are analysed through the theoretical concepts becomings, intensity, and glow.According to the results, when teachers capture unexpected comments, student engagement is aroused, allowing new concepts to enrich the SE content. In sum, this thesis concludes that SE needs to embrace more diverse content. This could be achieved through fluid conceptions of bodies and sexualities, thus facilitating students' recognition and subjectification, especially through the inclusion of nuances of asexuality, alternative family constellations, intersex, and crip. Finally, teachers need to welcome tensions and the unexpected as rich possibilities to capture new SE content and to create student engagement.
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| 27. |
- Koskiniemi, Sanna, et al.
(författare)
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Activation of cryptic aminoglycoside resistance in Salmonella enterica
- 2011
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Ingår i: Molecular Microbiology. - : Wiley. - 0950-382X .- 1365-2958. ; 80:6, s. 1464-1478
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Tidskriftsartikel (refereegranskat)abstract
- Aminoglycoside resistance in bacteria can be acquired by several mechanisms, including drug modification, target alteration, reduced uptake and increased efflux. Here we demonstrate that increased resistance to the aminoglycosides streptomycin and spectinomycin in Salmonella enterica can be conferred by increased expression of an aminoglycoside adenyl transferase encoded by the cryptic, chromo-somally located aadA gene. During growth in rich medium the wild-type strain was susceptible but mutations that impaired electron transport and conferred a small colony variant (SCV) phenotype or growth in glucose/glycerol minimal media resulted in activation of the aadA gene and aminoglycoside resistance. Expression of the aadA gene was positively regulated by the stringent response regulator guanosine penta/tetraphosphate ((p) ppGpp). SCV mutants carrying stop codon mutations in the hemA and ubiA genes showed a streptomycin pseudo-dependent phenotype, where growth was stimulated by streptomycin. Our data suggest that this phenotype is due to streptomycin-induced readthrough of the stop codons, a resulting increase in HemA/UbiA levels and improved electron transport and growth. Our results demonstrate that environmental and mutational activation of a cryptic resistance gene can confer clinically significant resistance and that a streptomycin-pseudo-dependent phenotype can be generated via a novel mechanism that does not involve the classical rpsL mutations.
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| 28. |
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| 29. |
- Lindkvist, Bjorn, et al.
(författare)
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Incidence and Prevalence of Primary Sclerosing Cholangitis in a Defined Adult Population in Sweden
- 2010
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Ingår i: Hepatology. - : Ovid Technologies (Wolters Kluwer Health). - 1527-3350 .- 0270-9139. ; 52:2, s. 571-577
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Tidskriftsartikel (refereegranskat)abstract
- Population-based studies on the epidemiology of primary sclerosing cholangitis (PSC) are sparse. The aim of the present study was to investigate prevalence and temporal trends in the incidence of PSC 1992-2005 in an adult population in Vastra Gotaland, a region in southern Sweden with a defined population of about 1.5 million. Patients with PSC aged 18 years or above were identified through a computerized search for diagnostic codes. A total number of 199 incident cases fulfilling Mayo criteria for PSC were identified through retrospective validation of clinical records. Temporal trends in the incidence of PSC were investigated by Poisson regression and expressed as average annual percent change (AAPC) with a 95% confidence interval (CI). The point prevalence of PSC on December 31, 2005, was 16.2/100,000 in the total adult population (men, 23.7/100,000; women, 8.9/100,000). The annual incidence was 1.22/100,000 in the total adult population (men, 1.78/100,000; women, 0.69/100,000). The overall incidence rate of PSC increased significantly over the investigation period (AAPC 3.06, 95% CI 0.01-6.20). Stratified analysis revealed significantly increasing trends for inflammatory bowel disease (IBD) associated PSC (AAPC 7.01, 95% CI 0.24-14.24) and large duct PSC (AAPC 6.32, 95% CI 0.03-13.02) in women and for PSC without IBD (AAPC 9.69, 95% CI 0.82-19.33) and small duct PSC (AAPC 17.88, 95% CI 0.95-40.25) in men. Conclusion: This is the first study to report a significantly increasing trend in the incidence of PSC. The prevalence of PSC at the end of the study period is the highest reported to date. This implies that the medical burden of PSC may be higher than estimated previously. (HEPATOLOGY 2010;52:571-577)
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| 30. |
- Liu, Yanling, et al.
(författare)
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Western Blotting via Proximity Ligation for High Performance Protein Analysis
- 2011
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 10:11, s. O111.011031-
-
Tidskriftsartikel (refereegranskat)abstract
- Western blotting is a powerful and widely used method, but limitations in detection sensitivity and specificity, and dependence upon high quality antibodies to detect targeted proteins, are hurdles to overcome. The in situ proximity ligation assay, based on dual antibody recognition and powerful localized signal amplification, offers increased detection sensitivity and specificity, along with an ability to identify complex targets such as phosphorylated or interacting proteins. Here we have applied the in situ proximity ligation assay mechanism in Western blotting. This combination allowed the use of isothermal rolling circle amplification of DNA molecules formed in target-specific ligation reaction, for 16-fold or greater increase in detection sensitivity. The increased specificity because of dual antibody recognition ensured highly selective assays, detecting the specific band when combinations of two cross-reactive antitubulin antibodies were used (i.e. both producing distinct nonspecific bands in traditional Western blotting). We also demonstrated detection of phosphorylated platelet-derived growth factor receptor beta by proximity ligation with one antibody directed against the receptor and another directed against the phosphorylated tyrosine residue. This avoided the need for stripping and re-probing the membrane or aligning two separate traditional blots. We demonstrate that the high-performance in situ proximity ligation-based Western blotting described herein is compatible with detection via enhanced chemiluminescence and fluorescence detection systems, and can thus be readily employed in any laboratory.
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| 31. |
- Nilsson, Maria, et al.
(författare)
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Radiation of extant marsupials after the K/T boundary: Evidence from complete mitochondrial genomes
- 2003
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Ingår i: Journal of Molecular Evolution. - : Springer Science and Business Media LLC. - 0022-2844 .- 1432-1432. ; 57:Suppl. 1, s. 3-12
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Tidskriftsartikel (refereegranskat)abstract
- The complete mitochondrial (mt) genomes of five marsupial species have been sequenced. The species represent all three South American orders (Didelphimorphia, Paucituberculata, and Microbiotheria). Phylogenetic analysis of this data set indicates that Didelphimorphia is a basal marsupial lineage followed by Paucituberculata. The South American microbiotherid Dromiciops gliroides (monito del monte) groups with Australian marsupials, suggesting a marsupial colonization of Australia on two occasions or, alternatively, a migration of an Australian marsupial lineage to South America. Molecular estimates suggest that the deepest marsupial divergences took place 64–62 million years before present (MYBP), implying that the radiation of recent marsupials took place after the K/T (Cretaceous/ Tertiary) boundary. The South American marsupial lineages are all characterized by a putatively nonfunctional tRNA for lysine, a potential RNA editing of the tRNA for asparagine, and a rearrangement of tRNA genes at the origin of light strand replication.
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| 32. |
- Nyholm, Maria, et al.
(författare)
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Higher education and more physical activity limit the development of obesity in a Swedish rural population The Skaraborg Project.
- 2008
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Ingår i: International Journal of Obesity. - London : Springer Science and Business Media LLC. - 1476-5497 .- 0307-0565. ; 32, s. 533-540
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Tidskriftsartikel (refereegranskat)abstract
- Objective:To investigate the prevalence and the secular trends of obesity in a rural Swedish community with emphasis on the association with socioeconomic status and lifestyle.Design:The Skaraborg Project cross-sectional population surveys were conducted in Vara, a rural community in the southwest of Sweden, every fifth year between 1977 and 2002.Subjects:A total of 3365 residents (1634 men and 1731 women) aged 30-60 years.Measurements:Obesity was defined as body mass index>/=30 kg m(-2). Information on ethnicity, marital status, socioeconomic status and lifestyle was collected by a questionnaire.Results:In 1977-1982, the average prevalence of obesity was 14% in both men and women, and in 2002, the prevalence of obesity was 19% in men and 21% in women. The age-adjusted odds ratio (OR) of obesity in 2002 was 1.48 (1.00, 2.20) in men and 1.41 (0.97, 2.05) in women. Without the simultaneous increase in the level of education and leisure-time physical activity (LTPA), the risk of developing obesity could have been considerably higher; in men OR=3.08 (1.88, 5.03) and in women OR=2.72 (1.66, 4.44). In multivariate models, higher levels of education and LTPA were associated with protective effects on obesity in both men (OR=0.60 (0.43, 0.83) and OR=0.50 (0.45, 0.79)) and women (OR=0.73 (0.54, 0.98) and OR=0.57 (0.42, 0.78)), respectively.Conclusions:This study revealed an upward secular trend in the prevalence of obesity in a rural community in Sweden. Increasing levels of education and LTPA limit this ongoing development of obesity. Public health strategies for the prevention of obesity should consider the special condition in rural environments.International Journal of Obesity advance online publication, 22 January 2008; doi:10.1038/sj.ijo.0803725.
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| 33. |
- Nyholm, Maria, et al.
(författare)
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The validity of obesity based on self-reported weight and height: Implications for population studies
- 2007
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Ingår i: Obesity. - Hoboken : Wiley. ; 15:1, s. 197-208
-
Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: To validate self-reported information on weight and height in an adult population and to find a useful algorithm to assess the prevalence of obesity based on self-reported information. RESEARCH METHODS AND PROCEDURES: This was a cross-sectional survey consisting of 1703 participants (860 men and 843 women, 30 to 75 years old) conducted in the community of Vara, Sweden, from 2001 to 2003. Self-reported weight, height, and corresponding BMI were compared with measured data. Obesity was defined as measured BMI > or = 30 kg/m2. Information on education, self-rated health, smoking habits, and physical activity during leisure time was collected by a self-administered questionnaire. RESULTS: Mean differences between measured and self-reported weight were 1.6 kg (95% confidence interval, 1.4; 1.8) in men and 1.8 kg (1.6; 2.0) in women (measured higher), whereas corresponding differences in height were -0.3 cm (-0.5; -0.2) in men and -0.4 cm (-0.5; -0.2) in women (measured lower). Age and body size were important factors for misreporting height, weight, and BMI in both men and women. Obesity (measured) was found in 156 men (19%) and 184 women (25%) and with self-reported data in 114 men (14%) and 153 women (20%). For self-reported data, the sensitivity of obesity was 70% in men and 82% in women, and when adjusted for corrected self-reported data and age, it increased to 81% and 90%, whereas the specificity decreased from 99% in both sexes to 97% in men and 98% in women. DISCUSSION: The prevalence of obesity based on self-reported BMI can be estimated more accurately when using an algorithm adjusted for variables that are predictive for misreporting.
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| 34. |
- Nyholm, Maria, et al.
(författare)
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What Is the Accurate Prevalence of Obesity in Sweden in the 21st Century? Methodological Experiences From the Skaraborg Project.
- 2008
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Ingår i: Obesity. - : Wiley. - 1930-739X .- 1930-7381. ; 16, s. 896-898
-
Tidskriftsartikel (refereegranskat)abstract
- Objective:To examine the impact of non-response to self-reported body weight and height in health questionnaires for the estimation of obesity prevalence.Methods and Procedures:A cross-sectional population-based health survey in the community ofVara with 16,009 residents (in year 2002) in South-western Sweden. Participants randomly selected in strata by sex and age among residents being 30-74 years old were consecutively invited to the local health care center for a health examination, including two visits. Self-reported information on body weight and height were obtained by health questionnaires at the first visit, and measured information on both variables at the second visit. For this study 1,809 subjects (904 men and 905 women) completed both visits (participation rate 81%), and a nurse measured body weight and height of all at visit two. Participants not self-reporting body weight and/or height at the first visit were defined as non-responders.Results:Both male and female non-responders were significantly older than responders. Female non-responders had significantly higher BMI (29.8 +/- 5.8 kg/m(2)) than female responders (26.6 +/- 5.3 kg/m(2)), (P < 0.001). No similar findings were seen in men. Non-responders were more likely to be obese than responders both in men (odds ratio (OR) 2.06, 95% confidence interval (CI) 1.03-4.11) and in women (OR 2.24, 95% CI 1.25-4.02).Discussion:Non-responders to self-reported body weight and height in health questionnaires contribute to the underestimation of obesity. Measured body weight and height are to prefer when describing the accurate prevalence of obesity in populations.Obesity (2008) doi:10.1038/oby.2007.134.
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| 35. |
- Persson, Malin, 1983-, et al.
(författare)
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In Vitro Motility Assay Studies at Low [MgATP] - Evidence For Inter-Head Cooperativity in Fast Skeletal Myosin II
- 2012
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Ingår i: Biophysical Journal. - : Biophysical Society. - 0006-3495 .- 1542-0086. ; 102:3 Suppl. 1, s. 146A-146A
-
Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- The idea that fast skeletal myosin II exhibits processivity with sequential actions of the two myosin heads during muscle contraction has long been a topic of discussion but with appreciable difficulties to obtain conclusive experimental results. The difficulties may be related to a limited processivity (few sequential head actions) that is of greatest importance at low velocity (e.g. high resistive load), difficult to study accurately in vitro. In order to aid the investigations we here make use of recent evidence that the bipyridine drug amrinone inhibits the strain-dependent ADP-release step of myosin II with expected enhancement of processivity (Albet-Torres et al., J Biol Chem., 2009); Månsson, Biophys J., 2010). For accurate velocity measurements, the recombinant expressed capping protein CapZ (Soeno et. al., J Muscle Res Cell Motil., 1998) was fluorescence labeled. Nanometer tracking was achieved by two-dimensional Gaussian fits to single molecule fluorescence intensity profiles representing CapZ attached to the trailing actin filament end. Importantly, the heavy meromyosin (HMM) propelled actin filament sliding velocity (1mM MgATP) for CapZ-capped filaments was comparable to that of uncapped filaments at different ionic strengths and HMM surface densities. Studies at low [MgATP] (5-30mM) suggests a non-linearity in the [MgATP]-velocity plot that was enhanced by 1mM amrinone. The result is in contrast to the linearity expected for independent myosin heads and could be interpreted as an apparent velocity dependence of the myosin step length. This is in accordance with the idea of limited processivity of myosin II if it is assumed that a doubled apparent step length corresponds to sequential action of the two heads. Further insight into the mechanism will be obtained using proteolytically prepared one-headed HMM and e.g. studies with external loads on actin.
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| 36. |
- Persson, Malin, 1983-, et al.
(författare)
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Transportation of Nanoscale Cargoes by Myosin Propelled Actin Filaments
- 2013
-
Ingår i: PLOS ONE. - : Public Library of Science. - 1932-6203. ; 8:2
-
Tidskriftsartikel (refereegranskat)abstract
- Myosin II propelled actin filaments move ten times faster than kinesin driven microtubules and are thus attractive candidates as cargo-transporting shuttles in motor driven lab-on-a-chip devices. In addition, actomyosin-based transportation of nanoparticles is useful in various fundamental studies. However, it is poorly understood how actomyosin function is affected by different number of nanoscale cargoes, by cargo size, and by the mode of cargo-attachment to the actin filament. This is studied here using biotin/fluorophores, streptavidin, streptavidin-coated quantum dots, and liposomes as model cargoes attached to monomers along the actin filaments ("side-attached") or to the trailing filament end via the plus end capping protein CapZ. Long-distance transportation (> 100 mu m) could be seen for all cargoes independently of attachment mode but the fraction of motile filaments decreased with increasing number of side-attached cargoes, a reduction that occurred within a range of 10-50 streptavidin molecules, 1-10 quantum dots or with just 1 liposome. However, as observed by monitoring these motile filaments with the attached cargo, the velocity was little affected. This also applied for end-attached cargoes where the attachment was mediated by CapZ. The results with side-attached cargoes argue against certain models for chemomechanical energy transduction in actomyosin and give important insights of relevance for effective exploitation of actomyosin-based cargo-transportation in molecular diagnostics and other nanotechnological applications. The attachment of quantum dots via CapZ, without appreciable modulation of actomyosin function, is useful in fundamental studies as exemplified here by tracking with nanometer accuracy.
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| 37. |
- Petersson, Jessica, et al.
(författare)
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The human IFN-inducible p53 target gene TRIM22 colocalizes with the centrosome independently of cell cycle phase.
- 2010
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Ingår i: Experimental Cell Research. - : Elsevier BV. - 1090-2422 .- 0014-4827. ; 316, s. 568-579
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Tidskriftsartikel (refereegranskat)abstract
- TRIM22 (Staf50), a member of the TRIM protein family, is an interferon (IFN)-inducible protein as well as a p53 target gene. The function of TRIM22 is largely unknown, but TRIM22 is suggested to play a role in viral defense by restriction of viral replication. In addition, TRIM22 may function as a ubiquitin E3 ligase. In contrast to previous reports showing solely cytoplasmic localization of exogenous TRIM22, we report here that endogenous TRIM22 is localized to both nucleus and cytosol in primary human mononuclear cells, as well as in the human osteosarcoma cell line U2OS. Moreover, we demonstrate a colocalization of TRIM22 with the centrosomes in primary cells as well as in U2OS cells, and show that this colocalization is independent of cell cycle phase. Additionally, our data suggest the colocalization with centrosomes to be independent on the microtubule network. Given that some viral protein assembly takes place in the close vicinity of the centrosome, our data suggest that important functions of TRIM22 such as regulation of viral replication and protein degradation may take place in the centrosome. However, further studies are warranted to certify this notion.
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| 38. |
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| 39. |
- Schoultz, Ida, 1979-, et al.
(författare)
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Infliximab reduces bacterial uptake in mucosal biopsies of Crohn’s colitis viamicrotubule-dependent pathway
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Background: A defective intestinal barrier, shown by increased paracellular permeability is an importantpathogenic factor in Crohn’s disease (CD). TNFα is a key mediator in the regulation of the intestinal barrierfunction. Treatment with antibodies directed against TNFα, such as infliximab, has been established as animportant part of the therapeutic arsenal in severe Crohn’s disease, but the mechanisms of action have yet tobe elucidated. Part of infliximab’s effect has been suggested to be reduced apoptosis of epithelial cells andthereby reduced paracellular permeability. Our aim was to study how infliximab affects uptake of adherent E.coli across the colonic mucosa in CD. Method: Seven patients with active CD colitis were examined before and after a four week treatment withinfliximab. Control biopsies were taken from healthy volunteers (4) and patients undergoing controlexamination for colonic polyps (4), aged 36 (range 25-81), coloscopy. Biopsies were taken from macroscopicallynon-inflamed descending colon and were mounted in Ussing chambers to study barrier function. Transmucosalpassage of green fluorescent protein (GFP) incorporated E. coli HM427, an adherent bacteria isolated from thecolon of a CD patient, was studied by quantifying the translocated fluorescent bacteria using flow cytometry. Results: Bacterial passage across the colonic mucosa was increased in CD (2500 ± 300 arb. units) comparedwith controls (960 ± 280; p<0.05), and was reduced to 500 ± 200 units after the infliximab treatment (p<0.05).In biopsies treated with colchicine (a microtubuline inhibitor) uptake of E. coli HM427 was reduced by 2/3compared to non-treated biopsies. Conclusion: Patients with active Crohn’s disease showed a defect in the barrier to adherent E. coli, which waspartly mediated through a microtubule dependent uptake. The four week treatment with infliximab improvedthe intestinal barrier to these bacteria. This may constitute an important part of infliximab’s mechanisms ofaction in active colitis.
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| 40. |
- Sieri, Sabina, et al.
(författare)
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Dietary fat and breast cancer risk in the European Prospective Investigation into Cancer and Nutrition.
- 2008
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Ingår i: American Journal of Clinical Nutrition. - : Elsevier BV. - 0002-9165 .- 1938-3207. ; 88:5, s. 1304-1312
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Epidemiologic studies have produced conflicting results with respect to an association of dietary fat with breast cancer.OBJECTIVE:We aimed to investigate the association between fat consumption and breast cancer.DESIGN:We prospectively investigated fat consumption in a large (n = 319,826), geographically and culturally heterogeneous cohort of European women enrolled in the European Prospective Investigation into Cancer and Nutrition who completed a dietary questionnaire. After a mean of 8.8 y of follow-up, 7119 women developed breast cancer. Cox proportional hazard models, stratified by age and center and adjusted for energy intake and confounders, were used to estimate hazard ratios (HRs) for breast cancer.RESULTS:An association between high saturated fat intake and greater breast cancer risk was found [HR = 1.13 (95% CI: 1.00, 1.27; P for trend = 0.038) for the highest quintile of saturated fat intake compared with the lowest quintile: 1.02 (1.00, 1.04) for a 20% increase in saturated fat consumption (continuous variable)]. No significant association of breast cancer with total, monounsaturated, or polyunsaturated fat was found, although trends were for a direct association of risk with monounsaturated fat and an inverse association with polyunsaturated fat. In menopausal women, the positive association with saturated fat was confined to nonusers of hormone therapy at baseline [1.21 (0.99, 1.48) for the highest quintile compared with the lowest quintile; P for trend = 0.044; and 1.03 (1.00, 1.07) for a 20% increase in saturated fat as a continuous variable].CONCLUSIONS:Evidence indicates a weak positive association between saturated fat intake and breast cancer risk. This association was more pronounced for postmenopausal women who never used hormone therapy.
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| 41. |
- Tolf, Conny, et al.
(författare)
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Characterization of polyclonal antibodies against the capsid proteins of Ljungan virus
- 2008
-
Ingår i: Journal of Virological Methods. - : Elsevier BV. - 0166-0934 .- 1879-0984. ; 150:1-2, s. 34-40
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Tidskriftsartikel (refereegranskat)abstract
- Ljungan virus (LV) is a suspected human pathogen isolated from voles in Sweden and North America. To enable virus detection and studies of localization and activity of virion proteins, polyclonal antibodies were produced against bacterially expressed capsid proteins of the LV strain, 87-012G. Specific detection of proteins corresponding to viral antigens in lysates of LV infected cells was demonstrated by immunoblotting using each one of the generated polyclonal antibodies. In addition, native viral antigens present in cell culture infected with LV strains 87-012G or 145SLG were detected in ELISA and by immunofluorescence using the antibodies against the VP0 and VP1 proteins. The anti-VP3 antibody did not react with native proteins of the LV virion, suggesting that the VP3 is less potent in evoking humoral response and may have a less exposed orientation in the virus capsid. No activity of the antibodies was observed against the closely related human parechovirus type 1. The polyclonal antibody against the VP1 protein was further used for detection of LV infected myocytes in a mouse model of LV-induced myocarditis. Thus, polyclonal antibodies against recombinant viral capsid proteins enabled detection of natural LV virions by several different immunological methods.
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| 42. |
- Tolf, Conny, et al.
(författare)
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Identification of Ljungan virus VP0 and VP1 amino acid residues associated with cytolytic replication in cultured cells
- 2009
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Ingår i: Archives of Virology. - : Springer Science and Business Media LLC. - 0304-8608 .- 1432-8798. ; 154:8, s. 1271-1284
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Tidskriftsartikel (refereegranskat)abstract
- Ljungan virus is a picornavirus isolated from Swedish and North American rodents. Replication of Ljungan virus in cultured cells normally induces a weak and delayed cytopathic effect compared to that of many other picornaviruses. However, efficiently replicating Ljungan virus variants may evolve during serial passages in cell culture. In this study, we evaluate the significance of three substitutions in capsid protein VP0 and VP1 of a cell-culture-adapted variant of the Swedish Ljungan virus 145SL strain. In contrast to the parental strain, this 145SLG variant grows to high titers in green monkey kidney cells and induces a distinct cytopathic effect. Reverse genetic analyses demonstrated that each one of the individual capsid substitutions contributes to lytic replication in cell culture, but also that expression of all three substitutions results in a 100- to 500-fold increase in viral titers compared to viruses encoding single capsid substitutions. In addition, as indicated by detection of activated caspase-3 and DNA fragmentation, there seems to be an association between increased replication efficiency of lytic Ljungan virus variants and induction of an apoptotic response in infected green monkey kidney cells.
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| 43. |
- Tolf, Conny, et al.
(författare)
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Molecular characterization of a novel Ljungan virus (Parechovirus; Picornaviridae) reveals a fourth genotype and indications of ancestral recombination
- 2009
-
Ingår i: Journal of General Virology. - : Microbiology Society. - 0022-1317 .- 1465-2099. ; 90, s. 843-853
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Tidskriftsartikel (refereegranskat)abstract
- Ljungan virus (LV) was discovered 20 years ago in Swedish bank voles (Myodes glareolus, previously referred to as Clethrionomys glareolus) during the search for an infectious agent causing lethal myocarditis in young athletes. To date, the genomes of four LV isolates, including the prototype 87-012 strain, have been characterized. Three of these LV strains were isolated from bank voles trapped in Sweden. Sequence analysis of an American virus (M1146), isolated from a montane vole (Microtus montanus) in western USA, indicates that this strain represents a genotype that is different from the Swedish strains. Here, we present genomic analyses of a fifth LV strain (64-7855) isolated from a southern red-backed vole (Myodes gapperi) trapped during arbovirus studies in New York state in the north-eastern USA in the 1960s. Sequence analysis of the 64-7855 genome showed an LV-like genome organization and sequence similarity to other LV strains. Genetic and phylogenetic analyses of the evolutionary relationship between the 64-7855 strain and other viruses within the family Picornaviridae, including previously published LV strains, demonstrated that the 64-7855 strain constitutes a new genotype within the LV species. Analyses also showed that different regions of the 64-7855 genome have different phylogenetic relationships with other LV strains, indicating that previous recombination events have been involved in the evolution of this virus.
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- Östberg, Anna-Lena, et al.
(författare)
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Tooth loss and obesity in a defined Swedish population
- 2009
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Ingår i: Scandinavian Journal of Public Health. - London, England : Sage Publications. - 1403-4948 .- 1651-1905. ; 37:4, s. 427-433
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Tidskriftsartikel (refereegranskat)abstract
- Aims: To explore the association between tooth loss and obesity in an adult Swedish population, and to investigate the influence of socioeconomy, life-style, and co-morbidity.Methods: A cross-sectional population health survey conducted in 2001-2005 in 2816 randomly selected Swedish men and women (age: 30-74 years; participation rate 76%). Main measures were; tooth loss: < 20 remaining teeth (self-reported), general obesity: BMI[≥]30 kg m-2, abdominal obesity: waist circumference > 88 in women and > 102 cm in men. Adjustments were made for socioeconomy, life-style, and co-morbidity.Results: 420 individuals (21.2%) had < 20 remaining teeth: 30-59 years 6.0%, 60-74 years 53.5%. Mean BMI was similar in men and women (26.9 kg m-2), however, both general and abdominal obesity was still more frequent among women (both p < 0.001). There was a significant interaction between age and tooth loss in the association with both general (p = 0.004) and abdominal obesity (p < 0.011) in men. In participants below 60 years of age, the association between tooth loss and general obesity (OR 2.17 [95% CI 1.51 - 3.12]) and abdominal obesity (2.23 [1.58 - 3.15]), respectively, was statistically significant independent of age and gender, and remained so also when accounting for differences in socioeconomy, life-style, and co-morbidity. There was no similar association in those 60 years or older. The findings in men and women were robust and concordant.Conclusions: Common mechanisms for oral health and obesity should be explored more also including longitudinal designs. The findings are important for targeting comprehensive interventions against obesity and tooth loss, especially among younger adults.
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