• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 5
  • 1
  • Tagged with
  • 11
  • 11
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 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.
1

From Virus Protection to Cell Isolation and Biomarker Discovery with Aptamers

Ghobadloo, Shahrokh January 2017 (has links)
New affinity molecules such as nucleic acid aptamers are in demand in the science and medical fields. Current aptamer selection technologies can generate unique aptamers with desired properties to targets of interest. My thesis describes a series of investigations on the protection of an oncolytic virus, the isolation of target cells from biological fluids, and aptamer-facilitated biomarker discovery. We tested individual aptamers and constructed a tetramer aptamer structure (quadramer) to increase virus infectivity. The quadramer protects vesicular stomatitis virus (VSV) during freeze–thaw cycles, shields the virus from neutralizing antibodies and increases viral active units. In addition to aptamers, we screened carbohydrate-based ice recrystallization inhibitors for the possible elimination of the cold chain of Vaccinia virus, VSV, and Herpes virus-1. N-octyl-gluconamide provides the longest shelf life for Vaccinia virus and Herpes virus-1 as tested according to the World Health Organization’s requirements for viral vaccines efficiency during transportation and distribution. We generated switchable aptamers capable of isolating cells expressing LIFR, NRP1, DLL4, uPAR, or PTCH1. These aptamers bind to the receptor positive cells in the presence of Mg2+ and Ca2+, and release the pure cells upon addition of EDTA. The aptamers were applied for a sequential positive immunomagnetic isolation of cells from mice bone marrow. We also utilized fluorescence-activated cell sorting (FACS) in our aptamer selections to develop switchable aptamers to positive isolation of monocytes from human blood. Moreover, we have selected non-switchable aptamers as an affinity probe to the cells expressing Axl receptor for immunofluorescent analysis and cell sorting. We determined aptamers to CD107a and applied them for biomarker discovery with mass spectrometry and found that CD107a was co-expressing with PD-1. Furthermore, we identified CD91 as binding partners to our aptamers in human monocytes using FACS and orbitrap mass spectrometry.
2

Mechanisms of volume regulation in murine choroid plexus epithelial cells

Hughes, Alexandra January 2010 (has links)
The choroid plexuses are largely responsible for cerebrospinal fluid (CSF) secretion and therefore play a fundamental role in brain homeostasis. The membrane proteins involved in CSF secretion are not fully known. Several electroneutral transporters have been identified by molecular methods in choroid plexus epithelial cells but there is a lack of functional data to support their expression making it impossible to elucidate their role in CSF secretion fully. The activity of many of these transporters can be observed in cell volume regulation. Thus, the main aim of the present study was to determine the ability of mammalian choroid plexus epithelial cells to regulate their volume in response to anisosmotic challenge and to investigate the transporters involved.Experiments were performed on cells isolated from the mouse fourth ventricle choroid plexus. Cells were isolated using a combination of manual perturbation, the enzyme dispase and a Ca2+ free incubation to disrupt tight junctions. Cell volume was measured using a video-imaging method. Cells used in this study were all of a similar morphology and had a mean volume of 0.71 pL.Cells exhibited a HCO3- dependent regulatory volume increase (RVI) in response to hypertonic challenge. Strong evidence is presented that the Na+/H+ exchanger (NHE1) and the Cl-/HCO3- exchanger (AE2) contribute to the RVI but the Na+K+2Cl- cotransporter (NKCC1) and the epithelial Na+ channel (ENaC) do not. Choroid plexus cells exhibit a HCO3- dependent regulatory volume decrease (RVD) in response to hypotonic challenge. The RVD was unaffected by DIOA (an inhibitor of KCC activity), the K+ channel inhibitors TEA+, Ba2+ or 4AP or the Cl- channel inhibitors DIDS or NPPB. However removal of extracellular Ca2+ completely abolished cell swelling in response to hypotonic challenge. This sensitivity of volume change to Ca2+ was specific to cell swelling as cell shrinkage in hypertonic artificial CSF was unaffected by removal of extracellular Ca2+.Thus functional evidence is presented to further elucidate the role of several proteins in the choroid plexus cell volume regulatory response to anisosmotic challenge.
3

Fraction of MHCII and EpCAM expression characterizes distal lung epithelial cells for alveolar type 2 cell isolation / MHCIIとEpCAMの発現解析による2型肺胞上皮細胞の高純度単離法の確立

Hasegawa, Kouichi 26 March 2018 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21000号 / 医博第4346号 / 新制||医||1027(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 岩井 一宏, 教授 中川 一路, 教授 伊達 洋至 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
4

Developing cultivated mollusks through establishing primary cell culture methods of Eastern Oyster, Crassostrea virginica, as a model bivalve

Aung, Thet Me Me 17 August 2022 (has links)
Cultivated seafood is a potential alternative protein source that can address the rising global food demand with exponentially rising human population growth. Cultivated seafood is made by growing animal cells in vitro using stem cells for edible food, eliminating the need to raise the entire animal. A crucial first step in developing cultivated seafood is creating a well-characterized cell line that can continuously grow and differentiate into desired cell types. Due to difficulties in determining optimal primary cell culture conditions, no continuous cell lines of food-relevant mollusks have been established so far. This study used the adult Eastern Oyster, Crassostrea virginica, as a model bivalve to study the decontamination, cell dissociation, and culture conditions suited for mollusk adductor muscle cells. Oyster adductor (OAD) cells were obtained via tissue explant, mechanical and enzymatic digestion. The cells were routinely monitored using an inverted microscope for phase-contrast and fluorescence imaging. Culture vessels were coated with surface proteins such as fibronectin, laminin, matrigel, and poly-d-lysine to promote cell attachment. The tissue decontamination with Penicillin-Streptomycin (100 µg/mL), Amphotericin B (0.25 µg/ml), and algaecide solution (0.03%) was effective in controlling microbial growth. OAD cells grew best at lower nutrient levels in a one-to-one ratio of Lebovitz L-15 media and artificial seawater. Lower fetal bovine serum levels, 1-5%, provided a high number of cell attachments and consistent growth in combination with 1% adult oyster whole-body or larvae extract. The tissue explant method resulted in the optimal cell dissociation from the three methods, and proceeding cultures had attached cells surviving for up to 10 days. All the plate coatings promoted cell attachment, but fibronectin provided optimal cell attachment of OAD cells. Fibroblast-like, neuron-like, epithelial-like, and rounded cells were observed. Fluorescence cell staining confirmed the presence of cytoskeleton and nuclei in the OAD cell cultures. These advances in primary cell culture methods of OAD cells may be beneficial for establishing mollusk cell lines for cultivated seafood production. / Master of Science in Life Sciences / For sustainable seafood production, alternative sources of seafood proteins are essential in ensuring food security in the future. Cultivated seafood is an alternative protein source to address this rising food demand without the need to raise, farm, or slaughter animals. In developing cultivated seafood, self-renewing stem cells of the animal of interest are grown and made into edible products. A crucial first step in making cultivated seafood is understanding the growth conditions of the primary cells taken from animal tissue. Marine mollusk composes a significant part of seafood consumption, and developing cultured mollusks can address the growing food demand as a seafood alternative. However, there are many gaps in understanding the biological and physiological requirements of mollusk cells. No continuous, self-renewing mollusk cells of food-relevant species have yet been established. This study used the adult Eastern Oyster, Crassostrea virginica, as a model bivalve to study the tissue decontamination, cell dissociation, and culture conditions suited for oyster adductor muscle (OAD) cells. OAD cells were obtained via three cell dissociation methods. Cell growth was routinely monitored using an inverted microscope. Cell-surface proteins such as fibronectin, laminin, matrigel, and poly-d-lysine were used to promote cell attachment. The tissue decontamination was effective with Penicillin-Streptomycin, Amphotericin B, and algaecide. OAD cells grew best at lower nutrient levels in the one-to-one ratio of Lebovitz L-15 media and artificial seawater. Lower fetal bovine serum levels, 1-5%, provided a high number of cell attachments and consistent growth in combination with 1% adult oyster whole-body or larvae extract. Various cell morphologies were observed in the OAD cell cultures. Fluorescence cell staining confirmed the presence of cytoskeleton and nuclei in the OAD cell cultures. These advances in cell culture methods of OAD cells may be beneficial for establishing mollusk cell lines for cultivated seafood production.
5

Skeletal Muscle Stem Cells

Kao, Grace W., Lamb, Elizabeth K., Kao, Race L. 18 July 2013 (has links)
Skeletal muscle satellite cells (myoblasts) are the primary stem cells of skeletal muscle which contribute to growth, maintenance, and repair of the muscles. Satellite cells are the first stem cells used for cellular cardiomyoplasty more than 20 years ago. The isolation, culture, labeling, and identification of satellite cells are described in detail here. The implantation and outcomes of cellular cardiomyoplasty using satellite cells have been summarized in the previous chapter (Chapter 1).
6

Skeletal Muscle Stem Cells

Kao, Grace W., Lamb, Elizabeth K., Kao, Race L. 18 July 2013 (has links)
Skeletal muscle satellite cells (myoblasts) are the primary stem cells of skeletal muscle which contribute to growth, maintenance, and repair of the muscles. Satellite cells are the first stem cells used for cellular cardiomyoplasty more than 20 years ago. The isolation, culture, labeling, and identification of satellite cells are described in detail here. The implantation and outcomes of cellular cardiomyoplasty using satellite cells have been summarized in the previous chapter (Chapter 1).
7

Novel Approaches to Cell Isolation in Simple Inertial Microfluidic Devices

Zhou, Jian 30 October 2012 (has links)
No description available.
8

In Vivo and In Vitro Characterization of Primary Human Liver Macrophages and Their Inflammatory State

Zimmermann, Andrea, Hänsel, René, Gemünden, Kilian, Kegel-Hübner, Victoria, Babel, Jonas, Bläker, Hendrik, Matz-Soja, Madlen, Seehofer, Daniel, Damm, Georg 02 May 2023 (has links)
Liver macrophages (LMs) play a central role in acute and chronic liver pathologies. Investigation of these processes in humans as well as the development of diagnostic tools and new therapeutic strategies require in vitro models that closely resemble the in vivo situation. In our study, we sought to gain further insight into the role of LMs in different liver pathologies and into their characteristics after isolation from liver tissue. For this purpose, LMs were characterized in human liver tissue sections using immunohistochemistry and bioinformatic image analysis. Isolated cells were characterized in suspension using FACS analyses and in culture using immunofluorescence staining and laser scanning microscopy as well as functional assays. The majority of our investigated liver tissues were characterized by anti-inflammatory LMs which showed a homogeneous distribution and increased cell numbers in correlation with chronic liver injuries. In contrast, pro-inflammatory LMs appeared as temporary and locally restricted reactions. Detailed characterization of isolated macrophages revealed a complex disease dependent pattern of LMs consisting of pro- and anti-inflammatory macrophages of different origins, regulatory macrophages and monocytes. Our study showed that in most cases the macrophage pattern can be transferred in adherent cultures. The observed exceptions were restricted to LMs with pro-inflammatory characteristics.
9

A Tiered Microchip System for High Purity Isolation of Rare Cells from Blood

Onur Gur (9713903) 15 December 2020 (has links)
<div>Rare circulating cells are becoming a subject of interest due to their potential clinical applications to replace invasive procedures. Due their low presence in blood (as low as 1 in 1 ml of blood) various platforms are developed to capture and isolate them. Common limitations of current platforms include the inability to process large volumes of blood without an initial volume reduction step such as centrifugation, reliance on a single antibody for the capture, and the difficulty of releasing and retrieving the captured cells with high purity. A rare cell retrieval platform with high throughput operation and high purity retrieval is needed to capture these rare cells by processing large volumes of blood.</div><div><br></div><div>In this thesis study, we have developed a two-tiered microchip system to capture and retrieve rare cells from blood samples with high purity. The first module of the system is a high throughput microfluidic interface that is used to immunomagnetically isolate targeted rare cells from whole blood, and discard > 99.999% of the unwanted leukocytes. The second module is a microwell array that furthers the purification by magnetically guiding each cell into a separate well concurrently, and allows individual retrieval of each cell. Even though the system we have developed is applicable to many fields pertaining to rare cell capture, here we demonstrate the proof-of-concept using model cell lines that represent circulating fetal trophoblasts. We describe the design, operation as well as the experimental characterization of the system. Our characterization results show that the process can be completed within 145 minutes from the very beginning till the retrieval of a target cell, and can provide efficiencies and purities that are as high as 100%. </div><div><br></div><div>In order to demonstrate a real-world use case for our device, we present preliminary experiments done with blood samples from pregnant women. We show that we are able to retrieve candidate fetal cells under 167 minutes. Future work will be focused on sequencing the candidate fetal cells retrieved from maternal samples to confirm their fetal origin as well as enhancing system performance in maximizing the number of cells captured.</div><div><br></div>
10

Metody detekce snížené imunitní odpovědi u pacientů po kardiochirurgické operaci / Methods for detection of impaired immune response in cardiac-surgical patients

Kormundová, Nikola January 2022 (has links)
In patients after cardiac surgery, there is an increase in the level of molecules with both pro-inflammatory and anti-inflammatory effects. This increase is influenced by the patient's clinical condition, but also by the nature of the operation itself, which uses conventional extracorporeal circulation. This technique leads to damage to blood elements by direct contact with air and parts of the extracorporeal circulation, as well as to ischemia-reperfusion injury. The specifics of cardiac surgery then affect possible postoperative complications such as multiorgan failure or septic shock. The diploma thesis is divided into a theoretical and a practical part. The theoretical part describes the principle and influence of cardiopulmonary bypass on the human body and the complications that are associated with its use. Furthermore, IFN-γ is described herein as a potential marker of septic conditions that could reflect the clinical postoperative condition of patients. The practical part of the diploma thesis monitored the percentage change of selected cell populations and the production of IFN-γ in the peripheral blood of patients before and after cardiac surgery. Furthermore, the response of individual isolated populations of healthy volunteers to selected stimulators was investigated. The percentage of...

Page generated in 0.1063 seconds