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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.
11

Telomerase Activity in Human Umbilical Cord Cell Populations Containing Hematopoietic Stem Cells

Murthy, Vidya 30 April 2002 (has links)
Hematopoietic cell populations exhibiting detectable telomerase activity and elongated telomere lengths display strong engraftment survivability in humans during transplants. We investigated telomerase activity and telomere length in umbilical cord blood hematopoietic cell populations obtained from ViaCell Inc. at various intervals of a two-week ex vivo stem cell amplification process. Telomerase activity is increased with time in ViaCell's amplification process, perhaps in response to the removal of differentiated cells and expansion of primitive hematopoietic stem cell populations in tissue culture media containing a mixture of growth factors. Two of ViaCell's cell culture fractions were analyzed for telomere length using a TLA. Our results showed relatively long telomere lengths for day-0 and day-14 cord populations, and that despite an upregulation of telomerase activity in Day-14 samples, a loss of about 2 kb of telomeric DNA occurs. Our data are consistent with a model in which the increase in telomerase activity in day-14 ex vivo amplified cord blood hematopoietic cells relative to fresh cord is sufficient to reduce, but not prevent, telomere shortening caused by cell proliferation. Lastly, we investigated various culture conditions that could potentially upregulate telomerase activity in the Day-14 amplified cells. However none of the treatments tested altered telomerase activity. Our detection of increased telomerase activity and relatively long telomere lengths in ViaCell's Day-14 ex vivo amplified cord blood stem cell fraction provides support for ViaCell's Selective Clonogenic AmplificationTM indicating a high engraftment potential for these cells.
12

Cord Blood Saving-Donation Model Study ¡V Bionet Incorp.

Chu, Jo-Lan 15 August 2007 (has links)
Abstract Along with the continuous merging innovations and break-through technologies on the development of stem cell study, there are more researching resources in the global market which have been invested in the studies of stem cell, and consequently stem cell can be utilized in more and more different fields. A professional biotechnology research institution; Jain PharmaBiotech, predicts that the market scale of stem cell collection and storage worldwide will reach 100 million US dollar in year 2010. Since the concept of stem cell application was introduced into Taiwan, a trend on the storage, and research and development of stem cell from cord blood has progressively arisen. The market of stem cell application will become more popular and the whole industry will be more well developed, especially when Taiwan Department of Health will allow the transplant of stem cell of cord blood being categorized into the ordinary surgical treatment, surgeons will have more experience on stem cell transplant and more successful cases will be conducted in the near future. However, the quantity of stem cell in cord blood and the chance of self-utilization have been the concerns and been questioned by the public now and then. Therefore, Bionet Corp. has been promoting a ¡§Donatable Family Banking (DFB)¡¨ project from middle of year 2004 and trying to address the above concerns. DFB project is expected to deliver the outcomes in protecting the self usage right of self payment clients on the stem cell saving of cord blood, and increasing the value and opportunity on the utilization of stem cell at the same time. Moreover, DFB project shall also be able to combine the advantages of public donation and self-saving, in order to increase the utilization rate on stem cell of cord blood, simultaneously not to cause any big financial burdens from the huge storage expenses, and eventually to reach a win-win situation between donators and service providers. In order to further verify the feasibility and confirmation of this innovative DFB project, a Analytical Hierarchy Process will be applied through analyzing the perspectives of economy, technology and medical ethics. Key terms Stem Cell; Cord Blood, Donatable Family Banking, Analytical Hierarchy Process
13

Potential Use of Umbilical Cord Blood Cells in Spinal Cord Injury

Chua, Shawn Julian 30 August 2011 (has links)
Spinal cord injury (SCI) pathophysiology occurs as a primary traumatic event followed by secondary injury, resulting in the loss of neurons, oligodendrocytes and demyelination of residual axons. Unfortunately, endogenous spontaneous regeneration of oligodendrocytes is minimal. Previously, a method to generate multi-potential stem cells (MPSC) from umbilical cord blood (UCB) has been reported using lineage negative cells (Linneg) grown in fibroblast growth factor 4 (FGF4), stem cell factor (SCF) and fms-like tyrosine kinase receptor-3 ligand (Flt-3l) supplemented serum free medium. These MPSC have the ability to differentiate into bone, muscle and endothelial cells. In this thesis, the ability of MPSC to differentiate into oligodendrocytes was investigated as a potential treatment for SCI. Culturing MPSC under conditions that mimic normal timing of oligodendrocyte differentiation resulted in cells that expressed oligodendrocyte markers in vitro and were morphologically similar to them. I next investigated the ability of MPSC to improve functional recovery in a SCI compression injury model. Although the cells did not differentiate into oligodendrocytes in vivo as we initially hypothesised, a modest but significant improvement in hindlimb function was observed. A cytokine assay revealed that MPSC secrete elevated levels of anti-inflammatory, angiogenic and neurotrophic factors, possibly contributing to indirect mechanisms of repair by reducing secondary injury. Shiverer mouse neonates were next used as an alternative non-injury model to investigate the differentiation potential of MPSC. We hypothesised that transplanting MPSC into a host with an immature immune system and an actively myelinating environment would lead to engraftment and differentiation into oligodendrocytes. However no MPSC that differentiated into oligodendrocytes could be detected. Altogether, our in vitro data adds support for the reprogramming of cells, with further studies needed to test the functionality of resulting oligodendrocyte-like cells. Although MPSC failed to differentiate in both in vivo models, several potential therapeutic targets to treat SCI were found.
14

Potential Use of Umbilical Cord Blood Cells in Spinal Cord Injury

Chua, Shawn Julian 30 August 2011 (has links)
Spinal cord injury (SCI) pathophysiology occurs as a primary traumatic event followed by secondary injury, resulting in the loss of neurons, oligodendrocytes and demyelination of residual axons. Unfortunately, endogenous spontaneous regeneration of oligodendrocytes is minimal. Previously, a method to generate multi-potential stem cells (MPSC) from umbilical cord blood (UCB) has been reported using lineage negative cells (Linneg) grown in fibroblast growth factor 4 (FGF4), stem cell factor (SCF) and fms-like tyrosine kinase receptor-3 ligand (Flt-3l) supplemented serum free medium. These MPSC have the ability to differentiate into bone, muscle and endothelial cells. In this thesis, the ability of MPSC to differentiate into oligodendrocytes was investigated as a potential treatment for SCI. Culturing MPSC under conditions that mimic normal timing of oligodendrocyte differentiation resulted in cells that expressed oligodendrocyte markers in vitro and were morphologically similar to them. I next investigated the ability of MPSC to improve functional recovery in a SCI compression injury model. Although the cells did not differentiate into oligodendrocytes in vivo as we initially hypothesised, a modest but significant improvement in hindlimb function was observed. A cytokine assay revealed that MPSC secrete elevated levels of anti-inflammatory, angiogenic and neurotrophic factors, possibly contributing to indirect mechanisms of repair by reducing secondary injury. Shiverer mouse neonates were next used as an alternative non-injury model to investigate the differentiation potential of MPSC. We hypothesised that transplanting MPSC into a host with an immature immune system and an actively myelinating environment would lead to engraftment and differentiation into oligodendrocytes. However no MPSC that differentiated into oligodendrocytes could be detected. Altogether, our in vitro data adds support for the reprogramming of cells, with further studies needed to test the functionality of resulting oligodendrocyte-like cells. Although MPSC failed to differentiate in both in vivo models, several potential therapeutic targets to treat SCI were found.
15

Evaluation of a Flow Cytometry Method for Identifying and Quantifying Fetal Red Blood Cells in Maternal Blood

Nilsson, Camilla January 2011 (has links)
Hemoglobin is an oxygen binding protein in erythrocytes. Hemoglobin is composed of four polypeptide chains. During the fetal stage the type of hemoglobin called fetal hemoglobin (HbF) dominates. After birth HbF is replaced by adult hemoglobin (HbA). HbF persists in concentrations less than 1%. Elevated concentration of HbF in adults exists in different conditions, Talassemi for example. When the uterus is damaged and the fetus doesn’t feel well its blood can pass the placenta barrier and enter the blood stream of the mother. A venous blood sample from the mother is analyzed to determine the status of the fetus. Laboratory Medicine Västernorrland already has two methods for analyzing HbF, one routine and one on call. The routine method needed to be replaced and the possibility to use flow cytometry was investigated. In this study, results from flow cytometry using Fetal Cell Count™ kit was compared to the results from the presently used methods, Kleihauer-Betke and HPLC. Cord blood was diluted with venous blood from an adult with the same blood group in various concentrations. A number of tests were performed and showed a fairly good correlation between the different methods. However more tests will be necessary to draw any clear conclusion.
16

Cryobiological characteristics of red blood cells from human umbilical cord blood

Zhurova, Mariia Unknown Date
No description available.
17

Cellular and Molecular Architecture of the Human Hematopoietic Hierarchy

Doulatov, Sergei 15 September 2011 (has links)
The blood system is organized as a developmental hierarchy in which rare hematopoietic stem cells (HSCs) generate large numbers of immature progenitors and differentiated mature blood cells. In this process, at least ten distict lineages are specified from multipotent stem cells, however the cellular and molecular organization of the hematopoietic hierarchy is a topic of intense investigation. While much has been learned from mouse models, there is also an appreciation for species-specific differences and the need for human studies. Blood lineages have been traditionally grouped into myeloid and lymphoid branches, and the long-standing dogma has been that the separation between these branches is the earliest event in fate specification. However, recent murine studies indicate that the progeny of initial specification retain the more ancestral myeloid potential. By contrast, much less is known about the progenitor hierarchy in human hematopoiesis. To dissect human hematopoiesis, we developed a novel sorting scheme to isolate human stem and progenitor cells from neonatal cord blood and adult bone marrow. As few as one in five single sorted HSCs efficiently repopulated immunodeficient mice enabling interrogation of homogeneous human stem cells. By analyzing the developmental potential of sorted progenitors at a single-cell level we showed that earliest human lymphoid progenitors (termed LMPs) possess myelo-monocytic potential. In addition to B-, T-, and natural killer cells, LMPs gave rise to dendritic cells and macrophages indicating that these closely related myeloid lineages also remain entangled in lymphoid development. These studies provide systematic insight into the organization of the human hematopoietic hierarchy, which provides the basis for detailed genetic analysis of molecular regulation in defined cell populations. In a pilot study, we investigated the role of a zinc finger transcription factor (ZNF145), PLZF, in myeloid development. We found that PLZF restrained proliferation and differentiation of myeloid progenitors and maintained the progenitor pool. Induction of ERK1/2 by myeloid cytokines, reflective of a stress response, leads to nuclear export and inactivation of PLZF, which augments mature cell production. Thus, negative regulators of differentiation can serve to maintain developmental systems in a primed state, so that their inactivation by extrinsic signals can induce proliferation and differentiation to rapidly satisfy increased demand for mature cells. Taken together, these studies advance our understanding of the cellular and molecular architecture of human hematopoiesis.
18

Asthma heredity, cord blood IgE and asthma-related symptoms and medication in adulthood : a long-term follow-up in a Swedish birth cohort

Vogt, Hartmut, Bråbäck, Lennart, Zetterström, Olof, Zara, Katalin, Fälth-Magnusson, Karin, Nilsson, Lennart January 2013 (has links)
Cord blood IgE has previously been studied as a possible predictor of asthma and allergic diseases. Results from different studies have been contradictory, and most have focused on high-risk infants and early infancy. Few studies have followed their study population into adulthood. This study assessed whether cord blood IgE levels and a family history of asthma were associated with, and could predict, asthma medication and allergy-related respiratory symptoms in adults. A follow-up was carried out in a Swedish birth cohort comprising 1701 consecutively born children. In all, 1661 individuals could be linked to the Swedish Prescribed Drug Register and the Medical Birth Register, and 1227 responded to a postal questionnaire. Cord blood IgE and family history of asthma were correlated with reported respiratory symptoms and dispensed asthma medication at 32–34 years. Elevated cord blood IgE was associated with a two- to threefold increased risk of pollen-induced respiratory symptoms and dispensed anti-inflammatory asthma medication. Similarly, a family history of asthma was associated with an increased risk of pollen-induced respiratory symptoms and anti-inflammatory medication. However, only 8% of the individuals with elevated cord blood IgE or a family history of asthma in infancy could be linked to current dispensation of anti-inflammatory asthma medication at follow-up. Elevated cord blood IgE and a positive family history of asthma were associated with reported respiratory symptoms and dispensed asthma medication in adulthood, but their predictive power was poor in this long-time follow-up. / <p>The status of this article was on the day of the defence date <em>Manuscript</em>.</p>
19

Prothymosin alpha, a gene differentially expressed in CD34+ cells

Waugh, Caryll Marie January 2004 (has links) (PDF)
Haemopoietic stem and progenitor cells from bone marrow and cord blood are well characterised with respect to their phenotype, growth in clonal assays, responsiveness to cytokine stimulation, receptor profile and their ability to sustain multilineage engraftment of receptive hosts in animal models of transplantation and of course, clinically in the treatment of some haemopoietic and immunological disorders. It is generally accepted that cells bearing the CD34+ phenotype are enriched for the most primitive of haemopoietic stem cells that possess the cardinal features of self-renewal and multipotency. However, the molecular mechanisms, the spectrum of expressed genes that give rise to the physical characteristics of haemopoietic progenitor cells are not well understood. Furthermore, although CD34+ cells from different sources (bone marrow, cord blood, mobilised peripheral blood) share many common features, there are also significant differences. (For complete abstract open document)
20

Frutose, sorbitol e glicose em sangue de mãe, cordão umbilical e recém-nascido de termo com 48 horas de vida

Barreiros, Rodrigo Crespo [UNESP] 24 November 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-11-24Bitstream added on 2014-06-13T21:06:10Z : No. of bitstreams: 1 barreiros_rc_dr_botfm.pdf: 473320 bytes, checksum: d48850cb60fbcfdb82cad35020b3bab2 (MD5) / A frutose é um açúcar derivado da glicose pela via do sorbitol presente em placentas de animais ungulados. Em humanos existem poucos relatos sobre a produção de frutose e de polióis pela unidade feto-placentária. Determinar a relação entre os níveis sangüíneos de frutose, sorbitol e glicose em mães, em veia de cordão umbilical e em recém-nascidos de termo em aleitamento materno exclusivo. As concentrações de frutose mais elevadas no cordão umbilical e no recém-nascido em relação às maternas sugerem que a produção de frutose à partir da glicose esteja presente na unidade feto-placentária e no recém-nascido. As concentrações de sorbitol mais elevadas no cordão em relação à mãe e no recém-nascido sugerem que as vias de produção de sorbitol estejam ativas na unidade feto-placentária. / Placenta from ungulates produce fructose from glucose by the sorbitol pathway using glucose as a substrate. In humans there are only few reports about the production of fructose and polyols by the fetal-placental unity. To determine the relationship between fructose, sorbitol and glucose blood levels from mothers, cord vein and breast-fed full-term newborns at 48 hours after delivery. Fructose concentrations in cord blood and newborn blood higher than maternal levels suggest that fructose production from glucose is active in fetal-placental unity and in the newborn. Sorbitol concentrations in cord blood higher than in mother and newborn blood suggest that the sorbitol pathway is active in fetal-placental unity.

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