Detection of C. botulinum in PCR-positive pig faecal samples by traditional isolation and characterization methods

A recently developed semi-quantitatively PCR procedure, specific in the detection of part of the types B, E and F neurotoxin genes, have been used to establish the prevalence of C. botulinum in faeces from slaughter pigs in Sweden. To verify PCR-positive samples, tests were performed to isolate and to identify C. botulinum by traditional microbiological methods and by mouse bioassay. Of twenty isolates from selective and non-selective media, two isolates were found positive by the preliminary screening e.g. lipase reaction and gelatine liquefication. None of the isolates were confirmed positive by RapiD ANA II, PCR or by the mouse bioassay. This describes the difficulties in isolating C. botulinum from heavily contaminated samples such as faeces, because of the lack of satisfactory selective media for C. botulinum and the presence of toxic compounds other than botulinum toxin in the sample

Function of Bruton's tyrosine kinase during B cell development is partially independent of its catalytic activity

The Tec family member Bruton's tyrosine kinase (Btk) is a cytoplasmic protein tyrosine kinase that transduces signals from the pre-B and B cell receptor (BCR). Btk is involved in pre-B cell maturation by regulating IL-7 responsiveness, cell surface phenotype changes, and the activation of lambda L chain gene rearrangements. In mature B cells, Btk is essential for BCR-mediated proliferation and survival. Upon BCR stimulation, Btk is transphosphorylated at position Y551, which promotes its catalytic activity and subsequently results in autophosphorylation at position Y223 in the Src homology 3 domain. To address the significance of Y223 autophosphorylation and the requirement of enzymatic activity for Btk function in vivo, we generated transgenic mice that express the autophosphorylation site mutant Y223F and the kinase-inactive mutant K430R, respectively. We found that Y223 autophosphorylation was not required for the regulation of IL-7 responsiveness and cell surface phenotype changes in differentiating pre-B cells, or for peripheral B cell differentiation. However, expression of the Y223F-Btk transgene could not fully rescue the reduction of lambda L chain usage in Btk-deficient mice. In contrast, transgenic expression of kinase-inactive K430R-Btk completely reconstituted lambda usage in Btk-deficient mice, but the defective modulation of pre-B cell surface markers, peripheral B cell survival, and BCR-mediated NF-kappaB induction were partially corrected. From these findings, we conclude that: 1) autophosphorylation at position Y223 is not essential for Btk function in vivo, except for regulation of lambda L chain usage, and 2) during B cell development, Btk partially acts as an adapter molecule, independent of its catalytic activity

Bruton's Tyrosine Kinase Cooperates with the B Cell Linker Protein SLP-65 as a Tumor Suppressor in Pre-B Cells

Expression of the pre-B cell receptor (pre-BCR) leads to activation of the adaptor molecule SLP-65 and the cytoplasmic kinase Btk. Mice deficient for one of these signaling proteins have an incomplete block in B cell development at the stage of large cycling pre-BCR+CD43+ pre-B cells. Our recent findings of defective SLP-65 expression in ∼50% of childhood pre-B acute lymphoblastic leukemias and spontaneous pre-B cell lymphoma development in SLP-65−/− mice demonstrate that SLP-65 acts as a tumor suppressor. To investigate cooperation between Btk and SLP-65, we characterized the pre-B cell compartment in single and double mutant mice, and found that the two proteins have a synergistic role in the developmental progression of large cycling into small resting pre-B cells. We show that Btk/SLP-65 double mutant mice have a dramatically increased pre-B cell tumor incidence (∼75% at 16 wk of age), as compared with SLP-65 single deficient mice (<10%). These findings demonstrate that Btk cooperates with SLP-65 as a tumor suppressor in pre-B cells. Furthermore, transgenic low-level expression of a constitutive active form of Btk, the E41K-Y223F mutant, prevented tumor formation in Btk/SLP-65 double mutant mice, indicating that constitutive active Btk can substitute for SLP-65 as a tumor suppressor

Cellular and Molecular Aspects of the Germinal Centre Reaction

The humoral immune response to a T cell dependent protein antigen will over time generate antibodies with an increased affinity to the antigen. This is due to a process known as affinity maturation and proceeds in a, for this purpose, well designed micro-milieu within secondary lymphoid organs known as germinal centres. The increase in affinity of an antibody in, e.g. mouse and man is due mainly to incorporation of single base-pair mutations, so called somatic mutations, in combination with an efficient competitive re-selection of better binders on the antigen held in its naïve form on follicular dendritic cells. Studies on affinity-maturation in human B cells and in cells within the germinal centre, have been hampered by the fact that the cells of interest die rapidly in vitro and the lack of a proper cell culture system for study of such cells. The aim of this thesis is to design such a cell culture system that allows growth of single human germinal centre B cells, known to accumulate somatic mutations in vivo, to study these single cell cultures for in vitro mutational activity, and to investigate signals required to induce naïve B cells towards a germinal centre B cell phenotype in vitro. By the use of a rapid screening system for in vitro accumulation of somatic mutations (RT-PCR and SSCP), clones raised from single cells were analysed for in vitro mutational activity. Human tonsillar, in vivo primed, germinal centre B cells were cultured together with murine EL-4 cells and shown to preserve some of their most characteristic extracellular phenotype and proliferation capacity. Still, no further in vitro accumulation of mutations were found in such single cell culture clones. Though, combination with interleukin-supplemented cultures based on CD40 crosslinking (via CD32 transfected murine L cells) of human GC-B cells revealed that their mutational activity could be preserved with one of the interleukin-combinations used, pointing out the importance of soluble factors for preserving the germinal centre reaction as well. In addition, signals required in vitro to differentiate resting B cells to a germinal centre B cell phenotype were identified. It was shown that stimulation via sIg and CD40, in combination with CD44, seem to drive the B-cell towards a GC-B cell phenotype. The role for CD4+CD57+ GC-T cells were also examined, and were shown to be able to rescue GC-B cells in vitro and drive peripheral blood B cells to Ig production by the addition of exogenous IL-2

Fat bloom on chocolate confectionery systems - From core to surface

Abstract Fat bloom on chocolate is a major problem for the confectionery industry since the unappetising appearance and negative sensory effects lead to rejection by customers. The presence of fat bloom on chocolate confectionery systems is usually connected to migration of liquid fat due to the difference in composition between filling triacylglycerols (TAGs) and cocoa butter TAGs. The filling TAGs migrate into the chocolate shell where they can dissolve cocoa butter crystals. Consequently, cocoa butter TAGs migrate to the surface followed by a re-crystallisation into the most stable polymorph β1VI. Cocoa butter is the main fat in chocolate which can be considered as a composite material consisting of solid particles (i.e. cocoa particles, sugar crystals and in some cases milk solids) in a lipid continuous matrix of cocoa butter. The final quality of the product is highly dependent on the polymorphic forms of the cocoa butter TAGs in the fat phase and the distribution and size of the solid particles. In this thesis the migration of filling oil into model shells of cocoa butter and of chocolate has been investigated as well as the fat bloom development. This was implemented through the development of novel analytical methods, where optical profilometry and confocal Raman microscopy give information regarding the shell microstructure at and below the surface, and energy dispersive X-ray spectroscopy (EDS) provides the opportunity to follow the movement of brominated TAGs from the filling into the shell. By combining these techniques with established methods such as low vacuum scanning electron microscopy (LV SEM) and differential scanning calorimetry (DSC) a toolkit for the investigation of oil migration connected to surface microstructure development has been established. Imperfections, in form of pores and protrusions, at chocolate surfaces have been identified, confirming previous studies reporting these features. These imperfections were characterised using confocal Raman microscopy indicating that some protrusions are filled with fat and some are air-filled in conjunction with a fat shell, while the pores consist of air. These imperfections continued further into the chocolate shell, thus, it is suggested that they could be connected to oil migration and further to fat bloom development. The microstructure of model shells was shown to have a substantial impact on the TAG migration rate which was connected to fat bloom development. By applying seeding as pre-crystallisation technique to the shells the migration rates were decreased as well as the development of fat bloom crystals at the surface. In contrast, model pralines with poorly tempered shells indicated a higher oil migration rate and accelerated development of fat bloom. Furthermore, the presence of non-fat particles was shown to increase the migration rate and the fat bloom development. Additionally, the particle size of the non-fat particles proved to have an impact, where a smaller particle size gave rise to higher migration rates and thus, accelerated fat bloom development. The importance of controlled storage temperature was further demonstrated, where a minor increase in temperature from 20 to 23°C lead to substantially higher migration rates and accelerated fat bloom development. The mechanisms of oil migration in chocolate confectionery systems have mainly been referred to as molecular diffusion or capillary flow in literature. However, through results from the work of this thesis, convective flow is suggested to be an important contribution to the migration of filling oil in addition to molecular diffusion and capillary flow

A directive to change the wor(l)d of sustainability reporting - An initial examination of non-financial disclosure by Swedish companies in light of the Directive 2014/95/EU

In 2014 the European Union officially announced the Directive 2014/95/EU concerning disclosure of non-financial and diversity information, and consequently as of the financial year 2017, certain large undertakings are required to annually report information concerning the impact of their business activities related to the thematic categories ‘environmental matters’, ‘social & employee-related matters’, ‘respect for human rights’ and ‘anti-corruption & bribery matters’. Motivated by the desire to facilitate non-financial reporting practices for disclosure to enhance more sophisticated decision-making by stakeholders, the Directive allows for significant flexibility to capture the multidimensional nature of social and environmental issues for increased relevance, consistency and comparability of disclosures by undertakings in all sectors and across Member states. The purpose of this study is therefore to determine the consequences of the Directive on non-financial information by outlining the regulatory effect on the level of disclosure on the thematic categories, and to examine the objective of ‘comparability’ among Swedish companies with 250-500 employees. For this reason, content analysis of quantitative and qualitative character was conducted on the non-financial disclosure by Swedish firms presented in written reports for 2016 and 2018. The results of this study demonstrate a positive change in the level of disclosure on the thematic categories between 2016 and 2018, illustrating the regulatory effect of the newly implemented regulation on non-financial information in Sweden. Moreover, based on the results of the qualitative content analysis it could not be concluded that non-financial disclosures on ‘respect for human rights’ was comparable as a result of the flexibility given by the Directive. Overall, results indicate that the flexibility given to foster materiality might hinder the comparability of non-financial disclosure. Findings of this study raises questions about the very design of the Directive and its ability to achieve its intended objective of enhanced decision-making for stakeholders.MSc in Accounting and Financial Managemen

A rock magnetic study of the Åkerberg gold deposit, northern Sweden

A rock magnetic study has been preformed of the Åkerberg gold deposit, located 30 km NE of Boliden in northern Sweden. The gold mineralization is located to a zone of subparallel quartz veins in a layered gabbro. Ground surveys show a lowering of the magnetic properties at the ore zone. This thesis addresses the factors causing the anomaly by investigating the magnetic properties of different parts of the gabbro. The thesis is also concerned with displacement of tectonic blocks, which is indicated by tilted magmatic layers in the immediate surroundings of the ore zone. Thermal and alternating field demagnetization and susceptibility and thermomagnetic measurements have been conducted on the samples collected at the ore zone and in distant parts relative to the ore zone. ChRM-directions have been analyzed with principal component analyses and one Virtual Geomagnetic Pole (VGP) was calculated. Mineral composition was examined with a Scanning Electron Microscope and conventional microscopy in both transmitted and reflected light. This study shows that the sampled outcrop distant to the ore zone is magnetite poor and that the gabbro lacks magnetite in the ore zone and in immediate surrounding areas. The NRM (Natural Remanent Magnetization) in the ore zone is carried by monoclinic pyrrhotite. The magnetic anomaly over the ore zone is caused by a lower amount of pyrrhotite compared to the surrounding areas. This study also indicates that the NRM carried by monoclinic pyrrhotite in the ore zone and in the distant parts of the gabbro was acquired during the same event. The timing of this event, however, is unclear since only one VGP could be calculated.En bergartsmagnetisk studie har utförts på en guldmineralisering som är belägen vid Åkerberg, 30 km Nordöst om Boliden, i norra Sverige. Mineraliseringen är bunden till en zon av subparallella kvartsgångar i en magmatiskt lagrad gabbro. Markbundna totalfältsmätningar av magnetismen visar en negativ anomali över malmzonen. I detta arbete har de magnetiska egenskaperna av området kring malmen, samt områden av gabbron som är mindre eller inte alls påverkade av malmlösningar undersökts. Arbetet syftar till att fastställa vad som orsakar anomalin. Detta arbete adresserar även tektoniska blockrörelser, vilket har observerats genom lutande lagring i närheten av malmzonen. Termisk- och växelströmsavmagnetisering har utförts på prover som inhämtats från malmzonen och mindre påverkade delar av gabbron. Utifrån dessa mätningar har olika vektorriktningar av NRM (Naturlig Remanent Magnetisering) analyserats och en så kallad VGP (Virtual Geomagnetic Pole) har beräknats. Ytterligare provundersökningar har varit susceptibilitet och termomagnetiska mätningar. Provernas mineralogiska sammansättning har undersökts med ett svepelektronmikroskop samt genom konventionell mikroskopering, så som i genomfallande och reflekterande ljus. Arbetet visar att magnetit som allmänt är ett av de vanligaste magnetiska mineralen, förekommer mycket sparsamt i de mindre påverkade delarna av gabbron (Fågelberget 1), samt att magnetit saknas i malmzonen och dess omgivning (Åkerberg 1 och Åkerberg 2). Det magnetiska mineralet i malmzonen är istället monoklin magnetkis. Den magnetiska anomalin är orsakad av en mindre mängd monoklin magnetkis i malmzonen jämfört med omgivande delar. Denna studie visar också att monoklin magnetkis i malmområdet, samt i mindre påverkade delar av gabbro, fick sin nuvarande NRM vid samma tidpunkt. Tidpunkten när detta hände har dock inte gått att fastställa då endast en VGP kunde beräknas

I knew there was something going on... : "Family members" experience of being close to a person with gender dysphoria during evluation and treatment.

Under de senaste 10 åren har gruppen som sökt hjälp för könsdysfori ökat. Personer med könsdysfori är särskilt utsatta för att utveckla psykisk ohälsa jämfört med befolkningen i övrigt. Det saknas dock kunskap om deras närståendes upplevelser. Den här studien är del av svenska könsdysforistudien, SKDS. Syftet med studien var att i en svensk kontext undersöka närståendes upplevelse av att leva nära en person som genomgår utredning och behandling för könsdysfori. Utifrån semistrukturerade intervjuer med elva närstående tolkades materialet genom induktiv tematisk analys. Analysen visade att de närstående upplevt att relationen fördjupats genom processen. Oavsett varierande reaktioner initialt har samtliga närstående landat i en vilja att genom fördjupad kunskap stå upp för den vårdsökande. För många har processen känts tung och ensam. Samsjuklighet och minoritetsstress har bidragit till ökad komplexitet och tyngd. Man har också hittat kraft i den gemensamma kampen. En slutsats är att den icke-dömande hållningen och oreserverade acceptansen hos de närstående, inte i samma grad återspeglats i internationella studier. En ytterligare slutsats är att de närstående utgör en viktig resurs i den vårdsökandes möjlighet till ett gynnsamt behandlingsutfall och att de närstående behöver uppmärksammas och erbjudas stöd för att själva kunna vara ett stöd.   Delstudie till Svenska könsdysforistudien (SKDS

I knew there was something going on... : "Family members" experience of being close to a person with gender dysphoria during evluation and treatment.

Under de senaste 10 åren har gruppen som sökt hjälp för könsdysfori ökat. Personer med könsdysfori är särskilt utsatta för att utveckla psykisk ohälsa jämfört med befolkningen i övrigt. Det saknas dock kunskap om deras närståendes upplevelser. Den här studien är del av svenska könsdysforistudien, SKDS. Syftet med studien var att i en svensk kontext undersöka närståendes upplevelse av att leva nära en person som genomgår utredning och behandling för könsdysfori. Utifrån semistrukturerade intervjuer med elva närstående tolkades materialet genom induktiv tematisk analys. Analysen visade att de närstående upplevt att relationen fördjupats genom processen. Oavsett varierande reaktioner initialt har samtliga närstående landat i en vilja att genom fördjupad kunskap stå upp för den vårdsökande. För många har processen känts tung och ensam. Samsjuklighet och minoritetsstress har bidragit till ökad komplexitet och tyngd. Man har också hittat kraft i den gemensamma kampen. En slutsats är att den icke-dömande hållningen och oreserverade acceptansen hos de närstående, inte i samma grad återspeglats i internationella studier. En ytterligare slutsats är att de närstående utgör en viktig resurs i den vårdsökandes möjlighet till ett gynnsamt behandlingsutfall och att de närstående behöver uppmärksammas och erbjudas stöd för att själva kunna vara ett stöd.   Delstudie till Svenska könsdysforistudien (SKDS