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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
81

Molecular characterization of vascular malformations using single-cell RNA sequencing and immunohistological analysis

Norrén, Amanda January 2023 (has links)
CCM is a human disease in which vascular malformations develop in the central nervous system, predominantly in the brain. The malformations which can measure up to several centimeters in size are dilated and leaky vessels, with unstable cellular junctions and thin vessel walls. Depending on the size and the location of the malformation, the lesion might impose a direct threat to the health of the patient. The symptoms vary from more mild health issues such as headaches, to more severe symptoms such as loss of vision or hearing, or even epileptic seizures, paralysis, and hemorrhagic strokes. CCM is caused by a mutation in either of the CCM genes: CCM1, CCM2, or CCM3. The molecular mechanisms underlying the development of the vascular malformations are still poorly understood, but it has recently been shown that the GTPase CDC42 interacts with the CCM protein complex. By inducing endothelial cell-specific deletion of Cdc42, similar malformations to that of CCM arise in the mouse brain. In this project, our aim was to investigate the molecular changes underlying the vascular malformations caused by endothelial specific Cdc42 deletion in mice. To do so, we isolated endothelial cells from Cdc42iΔEC and Control mouse brain at postnatal day seven and performed single-cell RNA sequencing of these cells. When analyzing the data, we noticed that a subset of KO cells clustered differently and showcased a unique molecular profile. These cells expressed pan-endothelial markers but did not classify as arteries, capillaries, or veins as they did not express markers for those endothelial sub-types. Instead, these cells expressed markers for fenestrated choroid plexus endothelium, such as Igfbp3, and Gpihbp1, yet the absence of Aqp1 expression distinguishes them from choroid plexus endothelial cells. To validate the results from the RNA sequencing experiments we performed immunohistochemistry on brain sections of Cdc42iΔEC and Control mice.   In summary, we identified a unique expression pattern in a subset of Cdc42 depleted endothelial cells. While further investigations are needed, this is an important starting point for the identification of potential biomarkers, drug targets and the development of urgently needed treatment strategies.
82

Development of immunoassays that can assess therapeutic bispecific antibodies on the Gyrolab platform

Hellberg, Ella January 2023 (has links)
No description available.
83

Discovery of peptides in Chinese medicinal plants

Afshar, Mostafa January 2021 (has links)
In this study, 20 well-known Chinese medicinal plants are included. Traditionally, these medicinal herbs were consumed for different diseases but have one application in common, treatment of rheumatism arthritis. Peptides are pharmacologically attractive substances and the reason behind this work as there is only one study on peptide content of included herbs. Commonly, plant-derived peptides are cysteine-rich peptides.  The plants were extracted in series by 60%, 30% and 10% AcN in H2O and FA. Then, the combined extracts were purified by SPE and SEC. Additionally, reduction by DDT, alkylation by IAM, and digestion by trypsin performed. UPLC-QToF was used for separation and identification of potential peptides.  The investigation resulted in finding peptides in Coix lacryma-jobi L, Atractylodes lancea, Astragalus membranaceus. Peptides found in these species are mainly in the range 2,5-5 kDa. This finding raises new questions about the function of peptides in these species and the possibility of having pharmacological activity.
84

Acquired and lost structure-functions of non-enveloped and enveloped viruses

Filipe, Diogo January 2022 (has links)
Viruses are biological entities that constantly affect the world around us and in many cases they can harm the health of humans and negatively impact food production, in agriculture andfisheries. The project concept is that, through the structural studies of viruses that infectsimple hosts, it is possible to point out structural features that are unique and conserved inviruses, that infect human, other animals, and crops, in the same phylogenetic lineage. Theseunique features have functionally been acquired, and are therefore potential drug and vaccinetargets. Standing on this concept, we aim to study three groups of pathogenic viruses: (i)Protozoan/Yeast Totiviridae and metazoan totivirus-like viruses, (ii) Invertebrate flavi-likeand vertebrate Flaviviridae viruses, and (iii) Invertebrate Mesoniviridae and vertebrateCoronaviridae viruses.First, we focused on acquired capsid structures of the totivirus-like Omono River Virus(OmRV). Unlike yeast Totiviridae viruses, the totivirus-like OmRV capsid presents surfaceprotrusion proteins, which are expected to be crucial for its extracellular transmission. Theinteraction between the capsid and the protrusion proteins is hypothesized to be largelymediated by amino acid residue T365 of the protrusion proteins. To clarify the function ofthese protrusion proteins we have successfully developed molecular tools, which are arecombinantly expressed protrusion protein and an OmRV infectious DNA clone with aT365A mutation. Although the excess of the protrusion proteins does not remarkably affectthe infectivity and binding capabilities of the OmRV particles, the OmRV with the T365Amutation shows a significantly reduced infectivity. Assuming that the infectivity was partiallyeliminated by the mutation, a putative transmission mechanism is associated with theprotrusion proteins. However, it is still under debate whether the protrusion proteins are anessential factor for extracellular transmission. Additionally, a new method was preliminarilyused for observing the interaction between the OmRV capsid and protrusion proteins usingdifferential scanning fluorimetry. The findings and the established methods can contribute tothe understanding of molecular mechanisms present in other pathogenic totivirus-like virusesthat affect fish, such as the salmon piscine myocarditis virus (PMCV).Secondly, we focused on acquired surface structures of vertebrate Flaviviridae andCoronaviridae viruses. Unlike the invertebrate flavi-like and Mesoniviridae viruses, thevertebrate viruses have acquired surface structures that are expected to be critical for evadinghosts’ adaptive immunity. To discover these acquired surface structure, it is necessary todetermine the surface structure of the invertebrate flavi-like and Mesoniviridae viruses. Herewe report the successful expression and purification of the invertebrate flavi-like Southernpygmy squid flavivirus (SpsFV) precursor/membrane-envelope (prM-E) protein and theMesoniviridae Nam Dinh virus (NDiV) p2a spike protein. The established expression andpurification system can be further used to resolve their structures using cryo-EM singleparticle analysis in future studies.
85

Cloning and characterization of an Arabidopsis thaliana arsenic reductase gene (ACR2)

Rahman, Aminur January 2010 (has links)
Arsenic is a toxic metalloid existing everywhere in the nature. It is toxic to most organisms and considered as human carcinogen. Arsenic contamination leads to severe health problems with diseases like damage of skin, lung, bladder, liver and kidney as well as central nervous system. It is very likely that too much chemicals such as cadmium and arsenic in the consumed foods can also lead to increased birth defects like spinal bifida. In some regions of South-East Asia, like Bangladesh, Burma, Thailand and India, arsenic contamination of human population via either food chain or drinking water is now considered as a national threat for mankind. As arsenic can be found everywhere in nature it may come in contact with food chain very easily through either water or cultivated crops. In South-East Asia the major cultivated crop is rice and it is the staple food for people in many countries like Bangladesh, Burma and Thailand. Cultivation of rice plants requires water either from rainfall or irrigation. Irrigated water in some regions of South-East Asia is highly contaminated with arsenic and by this way arsenic is accumulated in the rice corn which consumed not only by human but also by animals, birds and fishes. In order to avoid arsenic contamination in human food it is essential to find out a way to inhibit arsenic uptake in cultivated plants. Alternatively, we can also find out a way to metabolize arsenic "in plant". In my experiment I have used Arabidopsis thaliana as a model plant to isolate an arsenic reductase (ACR2) gene. This gene has been reported to be involved in metabolism, transport and sequestration of arsenic in plants. My thesis works include studies of the ACR2 gene based on characterization of the corresponding SALK mutants. All plants were exposed to arsenics under in vitro conditions. It was observed that the SALK mutants were more sensitive to arsenics in comparison with the wild type control plants. ACR2 gene was cloned from the genomic DNA of A. thaliana by using Phire Plant Direct PCR kits using database sequences as primers. The amplified product was first ligated to the vector pKOH152 and then transferred to E. coli DH5α competent cells. Recombinant bacterial colonies were screened by colony PCR to confirm the insertion of ACR2. The band (1.3 kb) obtained in gel image indicates that the ACR2 gene was cloned successfully. For further confirmation of these results the cloned gene should be sequenced.
86

Utilizing CRISPR/cas9-mediated technology to treat inherited retinal diseases : A systematic review

Rautavaara, Yedizza January 2022 (has links)
Inherited retinal diseases are considered as a leading cause of vision loss in a young population. Neither a permanent cure nor long-term treatment has yet been discovered. However, treating congenital visual impairment by utilizing a sequence-specific nuclease gene editing tool, CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats-associated protein 9), has appeared to have a positive impact in restoring eyesight. The following systematic review was implemented to gain more knowledge about the safety and efficiency features of CRISPR/Cas9 technology when used in clinical trials to treat inherited retinal diseases (IRDs). The review focuses on trials with Leber Congenital Amaurosis and Autosomal Dominant Retinitis Pigmentosa, common childhood IRDs. The studies were synthesized in a proportional meta-analysis using MedCalc software, and supplemented with a narrative literature review, considering both qualitative and quantitative data. The review covers different aspects related tothe use of CRISPR/Cas9s and provides an overview of IRDs and future treatment methods. In conclusion, CRISPR/Cas9, indeed, is seen as a potential technique to treat IRDs. However, different complications do arise, and researchers need to be reminded of the side effects and downsides of CRISPR/Cas9. So, they can further enhance this innovative gene-editing technique in exchange for ultimately achieving long-term treatments for blindness and other inherited diseases. / <p>Det finns övrigt digitalt material (t.ex. film-, bild- eller ljudfiler) eller modeller/artefakter tillhörande examensarbetet som ska skickas till arkivet.</p>
87

Application of Optogenetic Reporters to In vitro Cardiovascular Safety Models

Ved, Mansi January 2023 (has links)
No description available.
88

Development of a qPCR method for detection and quantification of Ustilago nuda and COX1 gene in Barley seeds

Ali, Umer Shaukat January 2023 (has links)
Barley loose smut caused by the fungal pathogen Ustilago nuda is a global concern with detrimental effects on barley production. Early detection of this infection is vital for effective disease supervision. However, current seed health testing protocols suffer from limitations in terms of time and efficiency. The present research work aimed to produce a method using qPCR for simultaneous screening of barley and U. nuda. A set of primers, 1F and 1R, was employed for the detection of rRNA operon internal transcribed spacer 1 sequence from U. nuda and a part of the COX1 gene, present in barley seeds, was selected as an internal control for comparison with U. nuda. A specific 79 bp target amplicon from a part of the COX1 gene was successfully amplified using COX1 F and COX1 R primers, and cloned into a vector for standard curve generation. However, attempts to replicate the previously published qPCR method by bachelor researcher for U. nuda internal transcribed spacer 1 sequence detection using 1F and 1R primers were unsuccessful. Several efforts were made to reproduce the results, but amplification was not observed. Further optimization, including literature review, primers and probe optimization is required to improve this method. The successful amplification of a part of the COX1 gene in both normal and infected samples underscore its potential as a reliable internal control. However, further research is necessary to refine the detection of U. nuda. This study underscores the need for continuous advancements in disease screening methodologies to meet global market demands.
89

Analysing rapeseed leaves from naturally infested fields in Skaraborg to detect Sclerotinia sclerotiorum using Nanopore sequencing

Siddiq, Muhammad January 2023 (has links)
Rapeseed is a versatile crop with significant economic value as fuel, food, and feed, contributing to farmers' income. However, its cultivation is often hindered by the devastating plant pathogen Sclerotinia sclerotiorum, which infects numerous plant species, including rapeseed. Stem rot disease caused by this fungus has historically caused substantial yield losses, ranging from 30 to 70% in Sweden, Germany, and the UK. The absence of disease-resistant cultivars poses a challenge for effective disease control. A real-time PCR is one of the several techniques used in laboratory for the detection of infection which has many benefits over conventional methods. But this study aimed to develop a technique for the detection of disease by confirming if MinION Nanopore Sequencing can be used for such purpose to save time, resources, and the environment as compared to real-time PCR and other conventional methods. Rapeseed leaves samples were collected from three naturally infested fields in Skaraborg; DNA was extracted and ITS regions which are commonly used marker or barcodes for identification of fungi were amplified with three different pair of primers. Amplicons were sequenced with MinION and hundreds of thousands of reads were recovered to Ascomycota and Basidiomycota fungi division while Saccharomycodes ludwigii fungi was the most abundant species recovered. Many pathogens were successfully detected while no single read of S. sclerotiorum could be recovered in the study. MinION is concluded to provide a fast and efficient method for the detection of plant pathogens however, in this study S. sclerotiorum were unable to be identified.
90

Role of arrestin beta-1 genetic mutation on insulin-producing beta-cell viability

Xie, Zexian January 2022 (has links)
No description available.

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