Kvalite inom patologi är viktigt och det finns flera steg i preanalysen som kan påverka diagnostiken. Fixering, dehydrering och snittning är viktiga steg där fel kan uppstå som påverkar diagnostiken. Fixering förhindrar autolys och att mikroorganismer inte kan tränga in i vävnaden. Det finns olika fixeringsmedel och ett vanligt fixeringsmedel är formalin. Dehydrering innebär att vattnet i vävnaden byts ut mot paraffin, vävnaden bör ha fixerats minst i 24 timmar innan. I processen läggs vävnaderna i olika bad, första steget är en låghaltig alkohol och sedan ökar styrkan på alkoholen för att minska att vävnaden krymper. Nästa steg är clearing som förbereder vävnaden för paraffin då alkohol och paraffin inte är blandbara med varandra, tillsist sker en infiltrering av paraffin. Syftet var att optimera dehydreringen för 5 mm vävnader med Logos. Nio olika dehydreringar utfördes där vävnaderna gick igenom formalin, etanol, isoparaffin, isopropanol och vax infiltrering. Vävnader som hade dehydrerats i 12 timmar blev hårda, torra och svårsnittade. Vävnader som dehydrerats under 7 timmar blev underdehydrerade och det förekom hål i snitten. Hud, uterus och tyroidea var svårsnittade medans appendix, njure, mjälte, navelsträng, placenta, adnex, gallblåsa och testikel gick lättare att snitta. Försök 1 hade en starkare infärgning än resterande försök. Anledning till att hål förekommit vid försöken kan bero på en överdehydrering som gör vävnaden torr och hård eller en underdehydrering som gör att partier blir mjuka. Det behöver göras flera försök för att uppnå den mest optimala dehydreringen för 5 mm vävnader, eller att programmet baseras på vävnadstypen. / Quality in pathology is important and there are several steps in the pre-analysis that can affect the diagnosis. Fixation, dehydration and sectioning are important steps where errors can occur. Fixation prevents autolysis and the microorganisms from penetrating the tissue. There are differernt types of fixatives and a common fixative is formalin. Dehydration means that the water in the tissue is replaced by paraffin, the tissue should have been fixed for at least 24 hours. In the process the tissues are placed in different baths, the first step is alcohol with a low precent and then the strength of the alcohol increases to reduce tissue shrinkage. The next step is clearing which prepares the tissue for paraffin because alcohol and paraffin are not miscible with each other. The purpose was to optimize the dehydration for 5 mm tissues with Logos. Nine different dehydrations were performed where the tissues went through formalin, ethanol, isoparaffin, isopropanol and wax infiltration. Tissues that had been dehydrated for 12 hours became hard, dry and difficult to section. Tissues that were dehydrated for shorter than 7 hours became underdehydrated and holes occurred. Skin, uterus and thyroid were difficult to section while the appendix, kidney, spleen, umbilical cord, placenta, adnex and testicle were easier to section. The first attempt had a stronger staining than the other attempts. Reasons why holes occurred in the attempts may due to an overdehydration that makes the tissue dry and hard or an underdehydration that makes parts of the tissue soft. Several attempts need to be made to achieve the most optimal dehydration for 5 mm tissues, or that the program is based on the tissue type.

Neuroblastoma is a tumour derived from cells of the nervous system and is the most common solid tumour in childhood. MYCN amplified and 11q-deleted neuroblastoma, two high-risk neuroblastoma were investigated in this study. RAD51 gene family includes six central genes for the dsDNA breaks repair by homologous recombination, which has been reported as important in varying types of cancer. The study aims to investigate if the dysregulation of this gene family could be involved in the unstable genome of 11q-deleted neuroblastoma, and to better understand the link between both high-risk tumours. The RAD51 family genes’ expression level was measured by RT-qPCR in samples of 11q-deleted and MYCN-amplified neuroblastoma that were treated with a UVC treatment and were recovered during varying hours. R2 database and DAVID were used to study the RAD51 family’s expression levels, associated event-free survivability, and altered pathways. RAD51 family is highly dysregulated in these tumours, four genes of six were found to be altered in high-risk neuroblastoma. Four of six genes presented altered expression levels in 11q-loss, and three of six in the MYCN-amplified case after the UVC treatment. The event-free survival probability analysis shown that the levels of expressions associated with high-risk neuroblastoma coincide with those that represent a poor life expectancy. Altered pathways were different in each type of tumour. 11q-deletion neuroblastoma’s pathways were associated with the nervous system development, and MYCN-amplified was related to the immune system. This study suggests that 11q-loss neuroblastoma presents a greater RAD51 family dysregulation compared with MYCN-amplified one, which could explain why its genome is unstable.

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Reduced levels of white adipocyte hormone adiponectin have been observed in obese individuals with type 2 diabetes (T2D). Higher adiponectin levels are monotonically associated with a lower risk of T2D and hence increasing circulating adiponectin levels is of great interest in diabetic research. A novel compound, called fibroblast growth factor 21 (FGF21), is showing great potential in treatment of obesity and T2D. In animal models with obesity and T2D FGF21 increases glucose uptake, improves lipid homeostasis, decreases fat mass and increases circulating adiponectin levels. In this study, theaim is to explore the acute effect of FGF21 on white adipocyte adiponectin secretion. Adiponectinsecretion experiments were performed on primary murine adipocytes incubated with FGF21 for 30minutes and adiponectin levels were measured with ELISA and normalised to total protein content.To study the signalling pathway of FGF21, a separate batch of murine adipocytes were pretreated with an Epac and PI3K inhibitor prior to addition of FGF21. Results from this thesis show that FGF21potently stimulates short-term adiponectin release via PI3K-dependent pathways with no effect on adiponectin synthesis.