No description available.

No description available.

Background: Vancomycin-resistant enterococci (VRE) is a common nosocomial infection. It classifies as Enterococcus faecalis or faecium carrying vanA or vanB gene that alters the bacterial cell wall hence lowering affinity for Vancomycin. Screening for VRE in Swedish hospitals are performed with stool sample pre-grown in selective broth followed by PCR and culture on selective media. Viasures Vancomycin resistance, Real Time PCR Detection Kit indicates that pre-growth in broth is not needed for the analyze. Aim: Comparison between the PCR kit and the subsequent culture on chromogenic agar with or without pre-growth in selective broth. Method: E. faecium with vanA gen (CCUG 36804) and E. faecalis with vanB gen (ATCC 51299) were suspended in different concentrations and added to ESwab transport medium. Thereafter small samples from the ESwab tube were enriched in selective broth. Samples from both selective broth and ESwab medium were analyzed with Viasures PCR kit on BD-MAX system and cultivated on chromogenic agar. Results: With pre-growth in selective broth the genes were found in every sample regardless of pre-concentration in the ESwab medium. Without enrichment the PCR kit always amplified the genes when the concentration was 40 000 cfu/ml for E. faecium (vanA) and ≥ 10 000 cfu/ml for E. faecalis (vanB). Colonies grew on chromogenic agar in every concentration from both ESwab and selective broth. Conclusion: Culture on chromogenic agar is comparable with or without pre-growth in selective broth but Viasure’s PCR kit is not equal for both methods in lower concentrations of the bacteria.

Practicing Motor Imagery (MI) with a Brain-Computer Interface (BCI) has shown promise in promoting motor recovery in stroke patients. A BCI records a person’s brain activity and provides feedback to the person in real time, which allows the person to practice his or her brain activity. By imagining a movement (performing MI) such as gripping with their hand, cortical areas in the brain are activated that largely overlaps with those activated during the actual hand movement. A BCI can provide positive feedback when the hand-related cortical areas are activated during MI, which helps a person to learn how to perform MI. Despite evidence that stroke patients may recover some motor function from practicing MI with BCI feedback thanks to the feedback provided from a BCI, the effectiveness and reliability of BCI-based rehabilitation are still poor.  A BCI can detect MI by analyzing patterns of features from the brain activity. The most common features are extracted from the oscillatory activity in the brain.  In BCI research, MI is often treated as a static pattern of features, which is detected by using machine learning algorithms to assign activity into a binary state. However, this model of MI may be inaccurate. Analyzing brain activity as dynamically varying over time and with a continuous measure of strength could better represent the cortical activity related to MI.  In this Licentiate thesis, I explore a method for analyzing the temporal dynamic of MI-activity with a continuous measure of strength. Brain activity was recorded with electroencephalography (EEG) and subject-specific feature patterns were extracted from a group of healthy subjects while they performed MI of two opposing hand movements: opening and closing the hand. Although MI of the two same-hand movements could not be discriminated, the continuous output from a machine learning algorithm was shown to correlate well with MI-related feature patterns. The temporal analysis also revealed that MI is dynamically encoded early, but later stabilizes into a more static pattern of brain activity. Last, to accommodate for higher temporal resolution of MI, I designed and evaluated a BCI framework by its feedback delay and uncertainty as a function of the stress on the system and found a non-linear correlation. These results could be essential for developing a BCI with time-critical feedback. To summarize, in this Licentiate thesis I propose a promising method for analyzing and extracting a temporal representation of MI, enabling relevant and continuous neurofeedback which may contribute to clinical advances in BCI-based stroke rehabilitation.

Methicillin-resistant Staphylococcus aureus (MRSA) is a variant of the more common Methicillin-Susceptible Staphylococcus aureus (MSSA), an opportunistic pathogen a portion of the human population carries as normal bacterial flora. When an outbreak of MRSA occurs, it is often important to determine if and how these strains are related to each other. In this report two different types of epidemiological methods were combined (namely Multi-Locus Sequence Typing and staphylococcal protein A-typing), in order to reduce workload, costs and time. A panel of resistance and virulence markers was also added to gather as much information about the culture as possible in a single analysis. To test the viability of the method extracted DNA and heat-treated bacterial cultures of both MRSA and MSSA were amplified with a curated panel of primers. These products were later sequenced with Nanopore’s MinION using the Flongle flow-cell. The method showed promise and worked as intended regarding the staphylococcal protein A-typing and the panel of resistance and virulence markers. However, the Multi-Locus Sequence Typing did still require optimization in order to be used clinically. In summary the project can be viewed as a success since it succeeded in being more time, cost and work efficient than many of its predecessors, when the problems with the Multi-Locus Sequence Typing are solved.

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Background: Niacinamide (NIA) is one of the most commonly used cosmetic ingredients. It belongs to the vitamin-B3 family and has extensive dermatological therapeutic benefits. NIA has been proven to be a useful skincare product in serving as anti-acne agent, preventing skin hyperpigmentation, removal of wrinkles from the face etc.  Aim: To investigate permeability patterns of NIA, its effect on electrical impedance of the skin membrane and the role it plays in maintaining the hydration of stratum corneum (SC). For this, permeation, chromatography, sorption isotherm and X-ray studies were performed. Results: NIA permeation was observed to correlate with pH and it permeated more when delivered in PBS at pH 7.4 as compared to its permeation in citrate buffer at pH 5. Moreover, skin resistance also increased by Ca. 47% in relation to NIA permeation at pH-5 while it decreased by an average of 45% at pH 7.4. In addition, vapor sorption analysis showed that NIA increased the hydration of SC at 95%RH as compared to buffer controls. This was also supported by X-ray data where NIA treated SC samples were shown to have larger interchain spacing in their keratin filaments in comparison to SC in buffer controls. This increase is usually associated with an increase in the water content of SC and thus NIA might have similar beneficial effects as water and can even be more advantageous as it doesn’t evaporate in dehydrated states unlike water. Moreover, artificial skin model has also been tested in parallel, and it was significantly more permeable to NIA than the human skin. Hence some modifications are necessary before it can be used to replace human/porcine skin. Conclusion: The study showed that pH influences NIA permeation and resistance of skin membrane. Additionally, NIA play beneficial roles by increasing water content of SC at high relative humidity (RH%).

Aripiprazol är den aktiva substansen i läkemedel för bipolaritet och schizofreni och metaboliseras av två enzym till den aktiva metaboliten dehydroaripiprazol. Till följd av interindividuella skillnader i aktiviteten hos enzymen samt att koncentrationen in vivo kan påverkas av andra läkemedel rekommenderas terapeutisk läkemedelsövervakning (TDM). Därmed har en selektiv och känslig vätskekromatografi- tandem masspektrometri (LC-MS/MS) validerats för kvantifiering av aripiprazol och dess aktiva metabolit dehydroaripiprazol i humant serum vid Specialkemi, Klinisk kemi och farmakologi vid Lunds universitetssjukhus utifrån interna kriterier byggda på riktlinjer från European Medicine Agency (EMA). LC-MS/MS analys utfördes på Tripple Quad 6500+ från AB Sciex med joniserande elektrospray (ESI) och multi reaction monitoring (MRM). Valideringen fastslog metodens mätområde till 4 – 2 500 nmol/L och kvantifieringsgräns till 4 nmol/L för respektive analyt. Metodens inomdags- och mellandags noggrannhet (variationskoefficient (CV%)) och riktighet (nominell differens) för kontrollprover (10 och 1 000 nmol/L) var mellan 3,5 – 9,1 % och mellan -6,8 – -13,0 för respektive analyt vilket var inom godkända kriterier. Innan metoden implementeras på kliniska prover bör framtida utvärdering undersöka om minimering av provsmittan är möjlig samt utvärdera långtidsstabiliteten av analyterna.

Overweight and obesity are a major problem today. It is a growing problem that harms health and is present in all ages. This study was designed to investigate the relationship between ISO-Body Mass Index in overweight children both boys and girls, and walking speed regardless of height. In addition, examine the relationship between weight, height and walking speed by using a six-minute walking test. The study included already collected measurements from the patients' first visit at the Energy Metabolic Laboratory, which is a research unit at the Department of Women's and Children's Health at the academic Hospital in Uppsala, between the years 2008–2021. Results were collected on 195 patients, 122 boys and 73 girls. Data collected were age, weight, height, walking speed, walking distance, heart rate, level of exertion and dyspnea. The results showed that the ISO-Body Mass Index affects walking speed in obese children. Regarding how walking speed differs between both genders of obese children, the results showed that higher ISO-Body Mass Index in boys leads to them walking more slowly compared to girls who are less affected. To be able to demonstrate how walking speed is affected by other continuous variables such as encouragement or motivation, more studies with greater focus on smaller age groups are needed to gain a better understanding of how the various variables affect walking speed.

Mitochondria are important cytosolic organelles present in nearly all eukaryotic cells. The main function of mitochondria are to generate the vast majority of ATP through the process of oxidative phosphorylation. Mitochondria have key roles regarding other systems in the body as well, such as regulation of apoptosis, calcium homeostasis, reactive oxygen production etc. Mitochondrial diseases are caused by impaired mitochondrial function, originating from mutations in either the mitochondrial DNA or the nuclear DNA. Epilepsy is a common symptom of mitochondrial disease, especially in children. The pathophysiology behind mitochondrial epilepsy is primarily based on ATP deficit, leading to a negative effect on a range of different nervous system related functions that in the end leads to seizures. The study aimed to investigate the effect on mitochondrial respiration of two commonly used antiepileptic drugs, namely valproic acid and Topiramate, and the anesthesic drug propofol, commonly used in case of refractory status epilepticus. The three drugs were titrated in different concentrations in a high-resolution respirometer from Oroboros Instruments (n=6). Propofol seemed especially inhibiting of mitochondrial function, and both propofol and topiramate had a significant decrease in mitochondrial respiration within the clinical concentrations. The result of the study supported research stating that propofol should be used with caution in patients with a mitochondrial disease, but further research should be done regarding all three drugs in order to draw definite conclusions.