Laminin motifs inserted into a recombinant spider drag-line silk protein increase the proliferation of human dermal fibroblasts

Spider silk is a promising biomaterial. It is highly biocompatible, non-toxic, most likely naturally degraded by the host organism over time and strong and resilient. Importantly, it consists of proteins and new motifs can relatively easily be added. While native spider silk is not possible to produce in available systems, a shorter segment of the protein, 4repCt, coding for 4 repetive alanine blocks and the C-terminal, can be inserted in vector and expressed in E-coli. Three laminin-motifs were added to 4repCt; RGD, IKVAV and YIGSR, in order to test how this affects cell proliferation of dermal fibroblasts. The results, although not confirmed with statistical certainty, strongly suggests that dermal fibroblast proliferation increase when grown on fibers with said motifs inserted compared to unmodified fiber. Fibers made with 4repCt are not as strong as native spider silk fibers. Therefore, cysteine was inserted into 4repCt, which allows production of potentially stronger fibers that can be subjected to tensile strength tests and disulphide brigde formation tests

In vitro testing of drug sensitivity in tumor cells from effusion

Malignant mesothelioma has a mean overall survival of around 1 year and lung adenocarcinoma with pleural spread has a mean overall survival of around 5 months. Both diseases cause fluid accumulation in the pleura, which is drained to alleviate associated symptoms such as shortness of breath. This fluid oft contains exfoliated tumor cells. All chemotherapy regiments in use against malignant mesothelioma and lung adenocarcinoma with pleural spread have an objective response rate of 30-40%, and they all increase mean overall survival with a mere 3 months. The choice of drug combinations in the chemotherapy regiments are determined based on the statistically best drug combination. However, due to tumor heterogeneity, it is unclear whether some patients would respond better to an alternative treatment rather than the gold standard. To test this hypothesis, tumor cells were isolated from the effusions and cultured together with cytostatic drugs. After 48 or 72 h, the toxicity was measured using an automated live / dead assay, a colorimetric assay or a flow cytometer based assay and compared to an untreated control. The obtained data was then compared with patient journals, either overall survival or effect of drug treatment. Such drug exposure assays have been performed for long, however, no drug exposure assay have seen clinical use outside of smaller studies. The work described in this thesis attempted a number of methods of improving these assays, most prominently by attempting to make the measurements tumor specific, as there is often a substantial admixture of benign inflammatory cells. Also other refinements were tested, such as increasing the concentrations of the tested drugs to above what is found in the blood of patients in order to elicit meaningful response during in vitro short drug exposure times. The thesis concludes with a promising study, using the flowcytometer to make the readouts tumor cell specific and to show high variation. Initial data suggests this tumor specific assay indeed is able to predict patient response to given drugs

Biologins bortglömda betydelse för gymnasievalet

Sociala modeller är idag dominerande som förklaringsmodell för könsskillnaderna över elevers förstahandsval till gymnasiet. Den slutsats sociala modeller ofta landar i är att berörda gymnasieprogram är otillräckligt jämställda. Detta leder till åtgärder som uppfattas "feminisera" den svenska skolan och gå ut över pojkarnas betyg. När könsskillnaderna istället förklaras genom biologiska modeller försvinner imperativet att ytterligare feminisera. I detta examensarbete undersöks därför om de sociala modellerna verkligen bör ha tolkningsföreträde, genom att undersöka statistik och genom två litteratursökningar. Resultaten visar att biologiska modeller presenterar en trovärdig alternativ tolkning genom en modell som heter dynamiska system. Examensarbetet avslutar med att argumentera för att fynd inom jämställdhetsforskningen bör tolkas både utifrån sociala och biologiska modeller