Neuroendocrine tumours generally show an overexpression of somatostatin receptors on their cell membranes, mainly subtype 2. This is taken advantage of in diagnosis and therapy by using synthetic somatostatin analogues that can be labelled with radionuclides to visualize and treat tumours with an overexpression of somatostatin receptors. The method traditionally used for visualization is somatostatin receptor scintigraphy (SRS) with 111In-DTPA-octreotide but this method is gradually being substituted by 68Ga-DOTATOC PET/CT. To evaluate patients for peptide receptor radionuclide therapy, it is mandatory for the patient to be examined by both methods. In the evaluation, the tumours are graded according to the Krenning scale on the images from the SRS. Patients with sufficient tumour uptake of somatostatin analogues are eligible for peptide receptor radionuclide therapy (PRRT). The aim of this study was to compare the tumour’s Krenning scores from SRS to the Krenning scores, quantitative indices and TNR-values from the 68Ga-DOTATOC PET/CT images. This was done to investigate if the Krenning scale could be applied to PET/CT enabling the patient to undergo only PET/CT for diagnosis and evaluation prior to PRRT. This study, including 28 patients, found no strong correlation between the Krenning scores from the SRS and the scores from 68Ga-DOTATOC PET/CT. However, a better correlation was shown between the Krenning scores from SRS and TNR-values where the quantitative indices SUVmax and SUVmean were divided with the SUVmean of the spleen. These findings could be worth exploring further in future studies, incorporating larger number of patients.

Background: Valvular heart disease (VHS) can be lethal. An auscultated murmur could be a first indication of VHS. Lately auscultation has been evaluated as non-accurate, while a murmur also can be normal/functional. The next step of verifying VHS, is a transthoracic echocardiography (TTE). The echocardiography clinic at Uppsala University Hospital has seen a lot of non-pathological referrals regarding murmur evaluation. Therefore, a fast-track screening TTE, performed by a biomedical scientist was of interest. Aim: The aim was to evaluate pathological possibility, regarding remitted patients with a new heart murmur. Material: The clinical quality work was based on remitted patients of ages 18 to 50. Sampling took place between November 2022 and Mars 2024, by Radiology Information System. Method: Type of murmur, outcomes and referring clinic was documented. Normal outcome group consisted of: absent VHS and mild VHS. Pathological outcome group consisted of: moderate and severe VHS. Probability was calculated based on systolic- and non-specified murmur. Result: Normal outcome group had 116 referrals and pathological outcome group had three referrals. Possibility of a pathological outcome became 2,5 %. Majority of the referrals came from the primary care (92 %). Conclusion: A systolic- and non-specified murmur had low possibility of a pathological outcome, which could indicate that a shorter screening TTE by a biomedical scientist is an option. A limitation was that the type of the remitted murmur could not be trusted. Majority of the referrals came from the primary care, which indicates that further clinical work at these facilities is necessary.

Biocides and antibiotics are commonly used in Irish agriculture. This could lead to accumulation at sublethal levels in water and resistance development. The risk of this has earlier been assessed as non-existent. However, resistant strains have been found in Irish farm waste water. Due to possible horizontal gene transfer between bacterial populations the risk may be higher. Antibiotic resistance mechanisms have worked against certain biocides and antibiotic resistant strains have in certain cases showed reduced biocidal susceptibility. The aim of this project was to characterise bacterial populations from Irish aquatic samples and investigate their susceptibility to agriculturally common biocides and relevant antibiotics. Isolates from Dublin Bay water samples (n=15) were characterised using basic techniques. Minimum inhibitory concentration (MIC) tests with a broth microdilution method were performed with eight biocides and complimentary minimum bactericidal concentration (MBC) tests. Antibiotic disc diffusions were performed with eight antibiotics. The samples contained gram-negative isolates (n=3), Staphylococcus aureus (n=1) and Bacillus spp. (n=8) isolates. All isolates were on average resistant towards methylated spirits and iodine at the 2% v/v starting concentration. MIC values for Tri Scrub and the generic biocide were high. All MBC values were on average higher than the corresponding MIC values. A significant amount of the Bacillus spp. isolates were resistant towards β-lactams. As there is statistical uncertainty around the results, further investigations are needed. In conclusion, a trend of both high MIC and MBC values while showing resistance towards the largest number of antibiotics could be seen in Bacillus spp. isolates.

Caseous lymphadenitis (CLA) is a disease primarily in sheep and goats, caused by Corynebacterium pseudotuberculosis, characterized by abscess formation in external and/or internal lymph nodes and organs. Economic losses occur due to emaciation, reduced milk production and impaired growth in affected animals. At the Swedish Veterinary Agency, bacterial culture is used as a diagnostic method for detecting CLA, requiring puncture of clinical abscesses. This sampling method increases the risk for disease transmission and overlooks animals affected by internal abscesses. In this study, a commercially available enzyme-linked immunosorbent assay (ELISA)-kit, based on an indirect ELISA, was validated for detecting antibodies for CLA, aiming for a more cost-effective and safer method that also can detect animals with internal abscesses. Serum and milk samples were analyzed to investigate the concordance between the two sample types. A subset of serum and milk samples was sent to Norway for analysis to compare the ELISA results, and comparison with another laboratory's results was conducted. The ELISA-kit demonstrated high sensitivity (92% for serum, 100% for milk), crucial for controlling CLA at herd level, while the specificity was estimated at 68% for serum and 61% for milk. To avoid increased and unnecessary culling of animals, a confirmatory method should analyze positive individuals to increase the specificity. Pooled milk samples could reduce costs for herd-level analysis, followed by serum sampling for positive herds.

Bacterial bloodstream infections represent a severe and potentially life-threatening condition. Diagnostic tools, providing rapid species identification and antimicrobial susceptibility testing have a great impact on disease progression and treatment optimization. Typically, antimicrobial susceptibility testing involves a time-consuming process, and faster methods are likely to contribute in clinical settings. This study aimed to assess the reliability of the European Committee on Antimicrobial Susceptibility Testing (EUCAST) rapid antimicrobial susceptibility testing (RAST) with a 16-20-hour incubation period for implementation in a clinical microbiology laboratory. This method was conducted alongside the standardized disk diffusion method from EUCAST, encompassing all bacterial species compatible with 16-20-hour RAST. The method was executed 80 times, and over 450 readings were performed. It confirms EUCAST's method validation, affirming 16-20-hour RAST as a swift and precise method for blood bacterial resistance determination. All inhibition zones were readable, with 89% of antibiotics tested falling within 1 mm of the set target value. Notable deficiencies were observed in antibiotic-species combinations, such as trimethoprim/sulfamethoxazole and gentamicin against E. coli, and erythromycin against S. pneumoniae. Accurate interpretation of inhibition zones demands precise reading practices as some zones were ambiguous. The study also underscores the importance of overnight cultures in antimicrobial susceptibility testing via standardized disk diffusion, accentuating 16-20-hour RAST's pivotal role in potentially accelerating resistance determination by up to a day. Given its commendable performance, 16-20-hour RAST is ready to be incorporated into the standard procedures at clinical microbiology laboratories, as demonstrated by its successful adoption at Unilabs, Skövde.

The ability of human pluripotent stem cells (hPSCs) to differentiate into different types of cells has been regarded as a significant discovery in the development of cell replacement therapy for type 1 diabetic patients. MicroRNAs can be transported to recipient cells via vesicles, so-called exosomes. Exosomal microRNA differ from those of the parent cells suggesting that cells possess an active selecting mechanism of exosomes and their contents. Therefore, microRNAs may directly or indirectly regulate the expression of pancreatic islet-specific transcription factors to control the differentiation and maturation of pancreatic islet cells. In this study, the dynamic expression of exosomal and intracellular microRNAs from human pancreatic islets were analyzed and were compared with that in stem cell-derived islet-like clusters. The study also aimed to analyze the expression levels of intracellular microRNA in human pancreatic islets and stem cell-derived islet-like clusters compared to exosomal microRNA extracted from human islet media and stem cell media, respectively. The primary method of exosome extraction was ultracentrifugation, followed by microRNA isolation using a kit. The exosomes were then characterized with NTA, and the isolated microRNAs were detected using RT-qPCR. The results showed that the expression of microRNAs was generally low in human islets compared to isolated exosomes. The microRNA expression levels in stem cell-derived islet-like clusters and their respective isolated exosomes were also analyzed and it showed that let-7a, miR-375 and miR-26a were more abundant in exosomes. The results can contribute to the generation of more functional stem cell-derived islet-like cell clusters prepared from hPSCs to some extent. However, continued research in this area is required.

Langerhansceller (LC) är en specifik typ av antigenpresenterande celler och är deenda residenta immuncellerna i epidermis. LC har likheter med både dendritiska celler och makrofager men kännetecknas av sitt uttryck av lektinreceptorn langerin (CD207) och lipid-antigenpresenterande komplexet CD1a. En rekonstruerad human epidermismodell är ett mycket användbart verktyg för olika typer av studier om epidermis, och integrering av LC i modellen ger även möjlighet till att studera immunologiska funktioner in vitro. Det har tidigare visatsatt perifera monocyter kan in vitro differentieras till LC med hjälp av granulocyt-makrofagkolonistimulerande faktor (GM-CSF), transformerande tillväxtfaktor beta1 (TGF-β1) och interleukin 4 (IL-4), men det finns olika beskrivningar på själva metoden. Syftet med den här studien är att etablera en metod för att differentiera perifera monocyter till LC, så att dessa sedan kan integreras i en epidermismodell. Resultatet från studien visar att huvuddelen av de differentierade cellerna befinner sig i suspension och behöver därför återföras till odlingen dag två vid byte av medium. Ingen väsentlig skillnad kan dock detekteras mellan de adherenta- och suspensionscellerna avseende andelen erhållna LC, vilket gör att suspensionscellerna kan med fördel användas för vidare studier. Det finns stor variation i utfallet av erhållna LC mellan blodgivare, men utbytet av LC kan förutses redan dag fyra. Sammanfattningsvis, i den här studien fastställdes en metod där monocyter från perifert blod differentieras till LC under sex dagar genom stimulering med GM-CSF, TGF-β1 samt pulsning med IL-4 detvå första dagarna, men vidare optimering är nödvändig innan dessa LC kanintegreras i en epidermismodell.

Cancer is one of the leading causes of death in the world, often due to failed treatments because of drug resistance. Treatment is difficult as resistance is hard to detect before treatment and can develop during treatment. The fluorometric microculture cytotoxicity assay (FMCA) is a reliable, rapid method for testing drug cytotoxicity but requires large cell samples, which can be challenging to obtain. Patient-derived cancer cells (PDC) have proven challenging to culture in monolayer models, but recent studies have shown the possibility of using tumoroids. Tumoroids are three-dimensional models where cells are grown in basement membrane matrix hydrogel, allowing scaffold growth like in vivo tumors. This study aimed to culture colorectal PDC in the form of tumoroids, transfecting them, and examine cell cycle and tumor resistance for 5-Fluorouracil, Oxaliplatin and Irinotecan. Cells were deposited in gels with medium mimicking in vivo conditions, supporting growth and allowing extracellular signaling. The study succeeded in culturing both untransfected and transfected cells, resulting in cells expanding 48 and 42 times, respectively. Cell cycle remained unchanged. No changes were observed in 5-Fluorouracil, but a change was seen in transfected cells at passage 3 with oxaliplatin. The cells showed a 22% difference in survival indexes compared to naïve cells. Changes were seen in Irinotecan’s half maximal inhibitory concentration (IC50); all cell passage IC50 values differed >15.17 µM (p-value 0.0184). In conclusion, PDC can be cultured as tumoroids, but more studies are needed to determine if the model can generate reliable results representing PDC regarding tumor resistance.

Background: Pulmonary Embolism (PE) is a potentially life-threatening condition that is characterized by one or several blood clots blocking the arteries in the lungs. The existing diagnostic tools for PE have their shortcomings, highlighting the importance of investigating new diagnostic methods. The development of non-invasive methods to collect microparticles from exhaled breath has opened possibilities to explore new potential biomarkers. SensAbues® is a sampling device that utilizes electrostatic filters to capture microparticles from the exhaled breath. The objective of this project was twofold: firstly, to assess the suitability of SensAbues® sampling device for a future proteomics study where the goal is to identify biomarkers for PE; and secondly, to evaluate the efficacy of various extraction solutions in retrieving proteins from the electrostatic filters. Materials and methods: Samples were collected from three healthy volunteers using the SensAbues® device. The electrostatic filters were then extracted using either PBS or 15% ethanol and the protein content was then estimated using a modified Bradford method. Additionally, two blank SensAbues® filter extracts, from PBS and 15% ethanol were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Results: The attempts to evaluate extraction solutions using the Bradford method were unsuccessful, as all the samples yielded negative values. The filter-blank extracts analyzed with LC-MS/MS contained a significant amount of polyethylene glycols of varying sizes. Conclusion: The polyethylene glycols from the SensAbues® filters may have interfered with the Bradford method. Polyethylene glycols can also interfere with proteins, making the SensAbues® sampling device unsuitable for the prospective proteomics study.

Introduction: Sleep apnea is a pathological health condition with repeatedly paused breathing during sleep. The condition can cause serious health problems and decrease quality of life. Offering a fast diagnosis and treatment could prevent further progress of the condition. The severity of sleep apnea is indicated by an apnea hypopnea index (AHI), which is scored based on a home sleep apnea test (HSAT). The purpose: This study compared the differences between manually and automatically scored AHI, to examine if the automatic scoring is an acceptable singular method for sleep apnea diagnostics. This study also examined if AHI differences could be predicted by HSAT airflow signal quality and the degree of central or mixed apneas. Methods: Sleep apnea patients were instructed by the author how to use the HSAT equipment, data of 182 one-night HSAT recordings were then collected. Each recording was analyzed automatically and manually by a sleep specialist, using the software Noxturnal 6.3. Results: There was a great correlation between the two AHI scoring methods (Spearman’s r 0,97), but a statistically significant difference was found. The positive predictive value (PPV) and negative predictive value (NPV) of the automatic method were 96% and 97%, respectively, sensitivity was 99% and specificity 84%. A moderate, negative correlation between signal quality and AHI differences (Pearson’s r -0,31) was found, but none with central apneas. Conclusion: The results were contradictory, but considering a low Cohen’s d, this study still concludes that clinical use of automatic AHI scoring should be sufficient if AHI > 15.