Dissertations / Theses on the topic 'Human cell culture - Effect of chemicals on'
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Manglik, Aparna Safety Science Faculty of Science UNSW. "Development of comparitive methods for chemical analysis and in vitro cytotoxicity testing of contaminated sites." Awarded by:University of New South Wales. School of Safety Science, 2006. http://handle.unsw.edu.au/1959.4/25168.
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This project developed methodology for in vitro toxicity assessment of contaminated sites using the Promega?? MTS [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxy-methoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium] assay performed on human cells (HepG2 and Skin fibroblasts). The project included the development of a method for extracting contaminants from soil based on leaching and centrifugation. A number of solvents and surfactants were assessed for their suitability as extracting agents. The Zwitterionic surfactant CHAPS ({3[(3-Cholamidopropyl) dimethylammonio] propanesulphonic acid}), which is an irritant in vivo, was found suitable for in vitro toxicity assessment applications. CHAPS was found to be the least toxic surfactant in vitro when tested on skin fibroblasts (NOEC: 1800??577 ppm, IC50: 4000??577 ppm) and HepG2 cells (NOEC: 833??289 ppm, IC50: 5300??287 ppm). The chosen surfactant was used in three different methods for extraction of Toluene and Xylene spiked in 2 g and 10g soil. The combination comprising of 0.1% (s/w) CHAPS and cosolvent 1% (w/w) Isopropanol, at their respective NOEC (No Observed Effective Concentration) toxicity values, showed good recovery of the nonpolar organic compounds in comparison to the recovery by 0.1% CHAPS and 0.5% CHAPS. The study found additive interactions to be the most common form of toxicity for 16 concentration combinations of Formaldehyde (polar), Toluene and Xylene (nonpolar) when compared to predicted toxicity (R2=0.943, P<0.0001). When assessing the in vitro toxicity of unknown (blind) contaminated soil samples, the Hazard Index (HI) predicted from the chemical analyses results showed a relatively good correlation (R2>0.7062, n=26) when compared to the experimental toxicity results on HepG2 cells. Furthermore, the comparison of Australian Health Investigation Levels (HIL) with in vitro toxicity testing gave similar correlation (R2>0.6882, n=26) on HepG2 cells. The overall project suggests the potential application of the zwitterionic surfactant (CHAPS) in sampling contaminants from soils in an in vitro toxicity assessment. This study demonstrates the application of in vitro toxicity assessment using human cells for the prediction of toxic risk as a sentinel to human toxicity from a contaminated site.
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Woo, Man-man Michelle, and 胡文文. "The effect of melatonin on human luteal cells." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2000. http://hub.hku.hk/bib/B31223746.
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Hau, Kwan-Leong. "Effect of embryonic stem cell culture condition on the cellular identities of human amniotic fluid stem cells." Thesis, Imperial College London, 2017. http://hdl.handle.net/10044/1/58021.
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Amniotic fluid stem cells (AFSCs) offer therapeutic potential for prenatal and neonatal diseases based on their unique features. From the development of embryos, AFSCs represent a category between embryonic stem cells (ESCs) and mesenchymal stem cells (MSCs), with AFSCs more primitive than MSCs. Our lab has previously established that AFSCs can be reprogrammed to regain functional pluripotency with valproic acid (VPA). However, detailed mechanisms are still unknown. Here, our results showed that Wnt signalling was downregulated in the initial stage and upregulated with VPA treatment; whereas mesenchymal-to-epithelial transition (MET) was not observed in the process. Additionally, our previous results demonstrated that AFSCs maintained in ESC conditions shared 82% transcriptome similarity with ESCs. In the second part of this study, we revealed that features of AFSCs including marker expression and differentiation ability were sustained better in ESC conditions. Regarding osteogenesis, enhanced osteogenic ability was found in AFSCs maintained in ESC conditions due to a TGF-beta/CD73-dependent signalling pathway. Moreover, in addition to possessing the same tri-lineage differentiation capability as MSCs, AFSCs can also be induced to express cardiac markers, but contractile cells have not been obtained yet. As features of AFSCs are better preserved in ESC conditions, a Wnt-dependent cardiomyocyte differentiation protocol for pluripotent stem cells is examined on AFSCs in the last part of this study. Our results showed that, with the Wnt-dependent protocol, cardiac markers were induced but spontaneously contractile cells were not observed. Taken together, our findings show that (1) Wnt signalling may play a role in VPA-induced reprogramming, (2) AFSCs maintained in ESC conditions can better maintain stem cell features, especially osteogenic ability through a TGF-beta/CD73 pathway, (3) With a Wnt-dependent protocol, AFSCs can be induced to express cardiac markers but not to become contractile cells.
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Gillett, M. L. "The effect of in vitro culture on the stability, expansion and neuronal differentiation of human pluripotent cell lines." Thesis, University College London (University of London), 2010. http://discovery.ucl.ac.uk/20315/.
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Pluripotent cells are defined by their ability to both self-renew and to differentiation into any cell type within the human body. As such, pluripotent cell lines are of great interest as starting material for drug screening and cell therapies for regenerative treatment of diseased tissues. Pluripotent cell lines were originally derived from germ cell tumors (embryonal carcinoma cells; EC), but have since been isolated and expanded from the inner cell mass of an early embryo (human embryonic stem cells; hESCs). This project set out to investigate the relative ability of the pluripotent NTERA2 (EC) cell line and hESC lines: Shef3, HUES7 and RH5, to differentiate into neurons, using mechanical and enzymatic culture methods. Focus was placed on monitoring differentiation efficiency and function between the different lines. The tumour origin, in addition to the poor reproducibility, low yield and reduced functionality of NTERA2 derived neurons, compared to primary neurons, makes their incorporation into regenerative therapies unlikely. As such, an enhanced neuronal differentiation protocol was developed for use in hESCs. Cell populations were monitored for relative changes in gene and protein expression at selected time points throughout differentiation using standard RT-PCR, Q-PCR and immuno fluorescence analysis. End stage neurons were screened for functionality using patch clamping and calcium imaging techniques. Monitoring of cellular behavior through differentiation was aided by the concurrent development of a portable microscope incubator stage in collaboration with Linkam scientific Ltd. These data demonstrate a variation in the ability to generate neurons from pluripotent cell lines, and suggests a predetermined, preferential cell fate within each line, even at the level of pluripotency. This study also characterises in detail neuronal differentiation from pluripotent cells, adding to the understanding which is essential for translation into therapies for neurodegenerative diseases such as Parkinson’s, Alzheimer’s, and Huntingdon’s disease.
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Goulet, Stéphanie. "Effect of corticosteroids and long-acting ß₂- agonists in a human cell culture based "in vitro" model of airway inflammation and tissue remodeling /." Basel : [s.n.], 2006. http://edoc.unibas.ch/diss/DissB_7631.
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Nyh, Johan. "From Snow White to Frozen : An evaluation of popular gender representation indicators applied to Disney’s princess films." Thesis, Karlstads universitet, Institutionen för geografi, medier och kommunikation, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-36877.
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Simple content analysis methods, such as the Bechdel test and measuring percentage of female talk time or characters, have seen a surge of attention from mainstream media and in social media the last couple of years. Underlying assumptions are generally shared with the gender role socialization model and consequently, an importance is stated, due to a high degree to which impressions from media shape in particular young children’s identification processes. For young girls, the Disney Princesses franchise (with Frozen included) stands out as the number one player commercially as well as in customer awareness. The vertical lineup of Disney princesses spans from the passive and domestic working Snow White in 1937 to independent and super-power wielding princess Elsa in 2013, which makes the line of films an optimal test subject in evaluating above-mentioned simple content analysis methods. As a control, a meta-study has been conducted on previous academic studies on the same range of films. The sampled research, within fields spanning from qualitative content analysis and semiotics to coded content analysis, all come to the same conclusions regarding the general changes over time in representations of female characters. The objective of this thesis is to answer whether or not there is a correlation between these changes and those indicated by the simple content analysis methods, i.e. whether or not the simple popular methods are in general coherence with the more intricate academic methods.Betyg VG (skala IG-VG)
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Van, der Stok Mary Elizabeth. "The cytotoxic effects of aflatoxin B1 and fumonisin B1 on cultured human cells." Thesis, 2004. http://hdl.handle.net/10413/7928.
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Aflatoxin B1 (AFB1) and Fumonisin B1 (FB1), potentially cytotoxic and carcinogenic mycotoxins are common contaminants of agricultural commodities in South Africa and thus could be detrimental to the human immune system. Many of the cytotoxic effects of AFB1 require its
bioactivation to an epoxide, which will bind covalently to macromolecules to form protein and DNA adducts. Fumonisin B1 is a competitive inhibitor of sphingosine and sphinganine N aceyltransferase, which are key components in the pathways for sphingolipid biosynthesis. Accumulation of free sphingoid bases, which are both cytotoxic and mitogenic, could provide a plausible explanation for the toxicity and carcinogenicity of FB1. The cytotoxic effects of AFB1 and FB1 on normal human lymphocytes, individually and in combination were assessed using the methylthiazol tetrazolium (MTT) bioassay. Two different methods of treatment were used, the treatment of isolated normal human lymphocytes for 12, 24, 48, 72 and 96 hours and whole blood treated for 12 hours. Flow cytometry and fluorescent microscopy were used to determine whether AFB1 and FB1 (5uM and 50uM), individually or in combination, were capable of inducing apoptosis, necrosis or nuclear fragmentation in isolated lymphocytes and whole blood
treated for 12 hours. DNA damage was evaluated using the comet assay. The results showed that AFB1routinely induced higher levels of cytotoxicity in isolated lymphocytes than FB1. In the combination treatment, the mitogenic properties of FB1 appeared to partially counteract the cytotoxic effect exerted by AFB1. When whole blood was treated with the same concentration and ratio of toxin, FB1 was shown to be more cytotoxic than AFB1. The
combination treatment of whole blood was shown to be cytotoxic in a dose dependent manner. The toxins appeared to exert a greater cytotoxic effect, when treated in combination than individually at higher concentrations. Aflatoxin B1 induced increased levels of apoptosis and necrosis in isolated lymphocytes while treatment with the FB1 resulted in increased levels of apoptosis at both concentrations. Treatment with the combination also resulted in increased levels of apoptosis. The levels of apoptosis were reduced in whole blood lymphocytes when compared to isolated lymphocytes. However, treatment with AFB1 and FB1 resulted in increased levels of apoptosis. Both AFB1 and FB1 are capable of inducing nuclear fragmentation.
Treatment with FB1 (5uM and 50uM) resulted in greater degree of fragmentation than AFB1. The most nuclear fragmentation was induced by the 5uM combination treatment. The 50uM combination treatment of isolated lymphocytes induced the most DNA damage. As both toxins are common contaminants and have been known to coexist, this could be a potential area of concern for public health.Thesis (M.Med.)-University of KwaZulu-Natal, 2004.
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McCanna, David. "Development of Sensitive In Vitro Assays to Assess the Ocular Toxicity Potential of Chemicals and Ophthalmic Products." Thesis, 2009. http://hdl.handle.net/10012/4338.
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The utilization of in vitro tests with a tiered testing strategy for detection of mild ocular irritants can reduce the use of animals for testing, provide mechanistic data on toxic effects, and reduce the uncertainty associated with dose selection for clinical trials. The first section of this thesis describes how in vitro methods can be used to improve the prediction of the toxicity of chemicals and ophthalmic products. The proper utilization of in vitro methods can accurately predict toxic threshold levels and reduce animal use in product development. Sections two, three and four describe the development of new sensitive in vitro methods for predicting ocular toxicity. Maintaining the barrier function of the cornea is critical for the prevention of the penetration of infections microorganisms and irritating chemicals into the eye. Chapter 2 describes the development of a method for assessing the effects of chemicals on tight junctions using a human corneal epithelial and canine kidney epithelial cell line. In Chapter 3 a method that uses a primary organ culture for assessing single instillation and multiple instillation toxic effects is described. The ScanTox system was shown to be an ideal system to monitor the toxic effects over time as multiple readings can be taken of treated bovine lenses using the nondestructive method of assessing for the lens optical quality. Confirmations of toxic effects were made with the utilization of the viability dye alamarBlue. Chapter 4 describes the development of sensitive in vitro assays for detecting ocular toxicity by measuring the effects of chemicals on the mitochondrial integrity of bovine cornea, bovine lens epithelium and corneal epithelial cells, using fluorescent dyes.
The goal of this research was to develop an in vitro test battery that can be used to accurately predict the ocular toxicity of new chemicals and ophthalmic formulations. By comparing the toxicity seen in vivo animals and humans with the toxicity response in these new in vitro methods, it was demonstrated that these in vitro methods can be utilized in a tiered testing strategy in the development of new chemicals and ophthalmic formulations.
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Shiu, Yan-Ting. "Effects of sickle erythrocytes on metabolism and gene regulation in cultured human endothelial cells under flow conditions." Thesis, 1999. http://hdl.handle.net/1911/19445.
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Sickle cell anemia is characterized by chronic hemolysis and episodic vasoocclusive crises. There are many factors contributing to vascular occlusion in sickle cell patients, with the enhanced, abnormal adhesion of sickle erythrocytes to endothelial cells being investigated most thoroughly. The vascular endothelium lining on blood vessel walls is in a unique position of direct exposure to these abnormal red blood cells. It is possible that interactions with sickle erythrocytes may modulate endothelial cells to create an environment sensitive to crisis-triggering factors and in favor of adhesion events. However, quantitative information on the metabolic and gene regulatory effects of these interactions on endothelial cells under flow is lacking.
In this research, we developed an experimental system that simulates the physiological vascular flow environment to subject cultured human endothelial cell (EC) monolayers to sickle cell perfusion with a well-defined wall shear stress level of 1dyne/cm2 for times up to 24 hours. Effects of sickle erythrocytes on EC production of vasotone mediators (prostacyclin and endothelin-1) and on EC expression of cell adhesion molecules (ICAM-1 and VCAM-1) were examined at the transcription and/or protein levels.
The production of prostacyclin and endothelin-1 both increased in ECs after exposure to sickle cell perfusion, in comparison to perfusion with normal red cells. The altered levels of prostacyclin and endothelin-1 may disturb the delicate balance of vasoactive materials, leading to vasotone instability in sickle cell patients. Gene expression and cell surface expression of ICAM-1 in ECs were profoundly elevated by perfusion with sickle erythrocytes. The elevation in membrane-bound ICAM-1 levels may increase the interactions between blood cells and ECs, especially leukocyte endothelium adhesion. This may lead to the entrapment of red cells in regions of low oxygen tension in the microcirculation and trigger the polymerization of sickle hemoglobin. VCAM-1 mRNA, but not membrane-bound VCAM-1, was also significantly increased by perfusion with sickle erythrocytes. The presence of VCAM-1 on ECs may enhance the adhesion of erythrocytes via binding to integrin VLA-4( a 4 b 1) expressed on sickle cell membranes, but not on normal red cell membranes. The release of soluble ICAM-1 and soluble VCAM-1 both increased in ECs after exposure to sickle cell perfusion, and may serve as an indicator of injury and/or activation of ECs. The presence of IL-1 b in the perfusion system, as a model of inflammatory cytokine effects, synergistically increased the production of prostacyclin, ICAM-1 and VCAM-1 in endothelial cells. This is consistent with the close association of inflammation and vasoocclusive crises observed in sickle cell anemia patients.
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Diamond, Scott Lee. "Effect of laminar shear stress on gene regulation, protein synthesis, and protein secretion by cultured human endothelial cells." Thesis, 1990. http://hdl.handle.net/1911/16336.
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To test the hypothesis that wall shear stress generated by blood flow may regulate endothelial cell expression of blood clot dissolving proteins or vasoactive proteins, an in vitro perfusion system was used to expose human umbilical vein endothelial cell monolayers to well defined, laminar fluid flow. Protein production studies utilized immunoassays, while semi-quantitative studies of messenger RNA levels in a small numbers of cells required a reverse transcription/polymerase chain reaction technique.
Secretion by endothelial cells of the two main regulators of the fibrinolytic (ie blood clot dissolving) system, tissue plasminogen activator (tPA) and plasminogen activator inhibitor, type 1 (PAI-1) were not affected by exposure to venous levels of shear stress (4 dynes/cm$\sp2$). However, at arterial shear stresses of 15 and 25 dynes/cm$\sp2$, the tPA secretion rate was 2.1 and 3.0 times greater, respectively, than the basal tPA secretion rate. PAI-1 secretion was unstimulated by shear stress over the entire physiological range. The tPA mRNA level was many fold higher ($>$10 fold) in endothelial cells sheared for 24 hours than in stationary controls. The mRNA level of the common house-keeping gene, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) was found to be the same in control and sheared cells. The fact that GAPDH was unregulated indicates selectively in cellular response to shear stress in addition to validating the PCR technique.
Endothelin (ET), a 21-amino acid peptide secreted by endothelial cells, has vasoconstrictor and mitogenic activity for vascular smooth muscle cells. Fluid shear stress of 25 dynes/cm$\sp2$ caused a rapid and sustained drop in endothelin production after only 2 hours exposure to shear stress. Endothelin secretion was not affected by venous shear stress of 4 dynes/cm$\sp2$. The mRNA level for endothelin in cells exposed to shear stress was almost undetectable, indicating that the drop in protein secretion is due to a drop in transcription of the message RNA for endothelin. The mRNA level of basic fibroblast growth factor (bFGF) was found to be the same in cells sheared for 24 hours as in controls.
Enhancement of the fibrinolytic potential of endothelial cells in response to hemodynamic forces involves transcriptional events and could explain the deposition of fibrin in low shear zones near arterial bifurcations. Flow-regulated ET expression may explain the inverse correlation of fluid shear stress with: (1) the localization of atherosclerotic lesions near vessel bifurcations and; (2) the severity of intimal hyperplasia in surgical vein bypass grafts and vessel anastomotic sites.
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Lin, Hsiu-Fen, and 林秀芬. "Effect of Transplantation with Cultured Human Adipose Tissue Derived Stem Cells on Rabbits Cornea RepairAfter Alkaline Chemical Burn ---- An Animal Study." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/16432366598597946283.
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碩士高雄醫學大學
職業安全衛生研究所
97
Chemical burn is the absolute ocular emergency. It is the most severe injuries to the organ of vision with a very high percentage of unfavorable outcomes. It often causes extensive damage and results in permanent visual impairment. Recurrent epithelial erosions, symblepharon, corneal scar, corneal ulceration, severe stromal inflammation, and corneal neovascularization are common clinical complications of alkali burn .We studied the effect of cultured human adipose tissue-derived stem cells on regeneration of rabbit cornea after alkaline chemical burn. Human adipose tissue–derived stem cells are served as the source of donor material. The frozen stem cells were defreezing and sub-cultured up to 80% with Keratinocyte -SFM (Invitrogen ) and supplements of EGF , BFE( Bovine pituitary extraction), 10 %FBS ( FBS 50 cc / SFM 500 cc),GM solution 100 ul / 500 cc SFM. The cell suspension was cultured in 25 cm2 culture flasks at 37oC and 5% CO2. Culture medium was replaced by 80-90 % every 2 days. The study was performed on 8 rabbits (2-2.5 kg) with alkaline burns of the cornea. NaOH-impregnated disks (impregnated for 5 minutes, size as 7 mm in diameter) were placed into strictly central cornea area for 40 sec. After removal of the disks, the eyes were washed with 20 ml saline for 30 sec. All the procedures were taken under general anesthesia (5% ketamine plus rompune 1 to 2 mg/kg IM) and local analgesia of the cornea (1% Proparacaine Hydrochloride). Immediately after the chemical burn, experimental animals received a single subconjunctival injection of stem cell suspension (1.3×105 cells/ 0.2 ml ml). Controls were injected with 0.2 ml saline. Topical treatment with gentamycin oint (twice per day) was applied for preventing secondary infections. The eyes were eviscerated after sacrifice on days 30. Histological studies were performed on paraffin sections stained with hematoxylin and eosin. Real-time PCR are performed to detect the surface markers of P 63, E-Catherin, Beta-catenin, and Connexin 43. We evaluate the corneal functions via the following criteria, corneal opacity assessments, Real-time PCR and Histology, to prove the corneal regeneration effects of human adipose tissue - derived stem cells. The average grading of experimental group is graded as 1-2 while the controlled group is graded as 4.This means the stem cells offer more cell renewal processes than the controlled group. Real-time for beta- catena, connexin43 (Cx43), E-Catherin, and P63 are checked, which represent as cell membrane, cell membrane, non-neural epithelium and corneal stratified epithelium individually. Positive correlation of beta- catenin, connexin43 (Cx43), E-Catherin means good cell renewal for damage repair of corneal epithelium related to chemical burn. P63 shows non-significant change. Histologically, there are 5-6 cell layers at epithelium for the experimental group and 2-3 cell layers for the controlled group. Except the 8th rabbits with poor section of histology, 6 experimental groups show 5-6 cell layers and 7 control group show 2-3 cell layers over the epithelia . Transplantation of cultured human adipose tissue derived stem cells on rabbits corneal chemical burn promotes cell renewal and damage repair. Corneal transparency, Real-time PCR, epithelium cell layers are evaluated and proved as positive for wound healing.
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Buckholz, Cheryl J. "Acute bioactivation and hepatotoxicity of ketoconazole in rat and the determinant presence of flavin-containing monooxygenase (FMO) isoforms in human duodenum, jejunum, ileum, and colon microsomes and Caco-2 cell line." Thesis, 2003. http://hdl.handle.net/1957/31055.
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Two specific goals were addressed for this dissertation. First to investigate
and identify the mechanistic profile of ketoconazole (KT)-induced hepatotoxicity
by utilizing in vivo and in vitro approaches determining the mechanism of action
for the hepatotoxicity incurred. To date, there has not been a mechanistic
determination of the hepatotoxicity associated with KT in vivo. This dissertation
evaluates the possible metabolic bioactivation of KT by cytochrome-P450 (CYP)
or flavin-containing monooxygenases (FMO) resulting in covalent binding with
hepatic macromolecules. The hypothesis of this study was to reveal whether
covalent binding by the parent compound, KT, and/or reactive metabolites
produces hepatic damage associated with increased serum alanine
aminotransaminase (ALT) release and decreased hepatic glutathione (GSH). The
first objective was determination of in vivo covalent binding in a dose-time
response comparison in Sprague-Dawley (SD) rat ALT and GSH levels. Increased
ALT and reduced hepatic GSH levels occurred. The second objective was an in
vitro comparison of covalent binding with GSH levels utilizing SD microsomal
protein with incubations of KT. Covalent binding decreased with added GSH to
microsomal incubations. Thirdly, correlate in vivo with in vitro findings. Covalent
binding of KT in vivo and in vitro occurred with increased doses and time. The
final objective was to determine the bioactivation pathway utilizing heat
inactivation and no NADPH in vitro. Covalent binding of KT decreased in the
absence of NADPH and deactivation of FMO.
The second goal was to determine and quantitate in vitro the presence of
FMO isozymes in microsomes of the human intestinal duodenum, jejunum, ileum,
and colon as well as the Caco-2 (HTB-37), epithelial intestinal (CCL-241) and
colon (CRL1790) cell lines. The presence of FMO could result in a first-pass effect
decreasing the bioavailability of soft nucleophiles or a toxicity effect due to
inhibition or modulation of the enzyme from co-administration. To date, this is the
first evaluation of FMO isoforms in human intestine and cell lines. Western blot
techniques were utilized for detection of human FMO1, FMO3, and FMO5 using
human FMO-expressed recombinant cDNA from a baculovirus system.Graduation date: 2003
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HUANG, CHUNG-YUEH, and 黃中岳. "1. The effect of aqueous extract of Prunella vulgaris in suppressing invasion and migration in human non-small cell lung cancer cells. 2. Identification of novel small chemicals with autophagic clearance of polyglutamine aggregation in human neuroblastoma cells." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/51288579547742351837.
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碩士國立臺灣師範大學
生命科學研究所
100
1. Cancer cells grow and duplicate unregulated that form malignant tumors. The capability of cell invasion and migration from the origin site (metastasis) to nearby parts is the most threating. Cancer metastasis starts with the degradation of extracellular matrix (ECM). Both invasion to nearby tissue of cancer cell and inducement to angiogenesis relies on the matrix metalloproteinase (MMP) activity for ECM degradation. The thesis focused on treating cell lines, A549 (wild type p53 human adenocarcinoma), H460 (human large cell lung carcinoma) and H1299 (p53 deleted human adenocarcinoma) with Chinese herb medicine (CHM), and then detect changes of MMP-9 and MMP-2 activities by evaluating gelatin zymography. Both gelatin zymography and western blot to find out whether CHM can inhibit the MMP-9 and MMP-2 expression. The work is also to figure out whether MMP-9 and MMP-2 inhibition affects the migration and invasion capacity of the cancer cells. We have found that the aqueous extract of Prunella vulgaris can affects MMP-9 and MMP-2 activities in human lung carcer cells, and inhibit the invasion and migration of cancer cells. The other goal of this thesis is to find out new CHM‘s that are capable of inhibiting tumor angiogenesis and metastasis by evaluating MMP-9 and MMP-2 activities in human hepatocarcinoma cells. 2. Cells digest unwanted substance by autophagy, a procedure that could reuse building blocks from unwanted substances and clarify poisonous substance. The recycled substrate is covered by lipid bilayer, forming autophagsome that combines lysosome for digestion. Polyglutamine (polyQ) disease is a set of genetic disorder caused by the increased numbers of CAG or CUG repeats in some neurodegenerative diseases. Drugs that induced up-regulation of autophagy have been proved decrease the toxicity of polyQ aggregation in mouse model of Huntington’s disease. Thus, the autophagy-inducing drugs promise to be an effective therapy of polyQ diseases. The thesis used SK cell lines transfected with green fluorescent protein conjugated with different length of polyQ. The purpose is to find out whether the autophagsome can be increased by treatment of different compounds and whether they affect the viabilities of the cells. Three compounds were found capable of inducing cell autophagy and decreasing polyQ aggregration in cell models. In the future, the research will focus on how the selected drugs affect autophagy and test the drugs in animal model.
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Chu, Stephanie S. T. Y. "Effect of human equilibrative nucleoside transporter 1 (hENT1) and ecto-5' nucleotidase (eN) in adenosine formation by neurons and astrocytes under ischemic conditions." 2012. http://hdl.handle.net/1993/8353.
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Adenosine (ADO) is an endogenous neuroprotectant. Under ischemic conditions ADO levels rise in the brain up to 100-fold. ADO in the brain is dependent on the movement across cell membranes by equilibrative nucleoside transporters (ENT) or produced from membrane bound ecto-5’ nucleotidase (eN). We used transgenic neurons with neuronal specific expression of human ENT1 (hENT1) and eN knockout (CD73 KO) astrocytes. The aim of this research was to determine the role of ENT1 and eN in ADO release from ischemic-like conditions in primary cultured neurons, astrocytes or co-cultures.
Neurons primarily release intracellular ADO via ENTs; this effect was blocked by transporter inhibitor, dipyridamole (DPR). Astrocytes primarily convert ADO extracellularly from eN; this effect was with eN inhibitor α, β-methylene ADP (AOPCP). Combined neuron and KO astrocytes produced less ADO, extracellular ADO was inhibited by DPR but not AOPCP. Overall these results suggest that eN is prominent in the formation of ADO but other enzymes or pathways contribute to rising ADO levels in ischemic conditions.
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Lawson, Karla Ann. "Investigation of the effect of a novel vitamin E derivative (alpha-TEA) alone and in combination with a known chemotherapuetic agent in human breast cancer using cell culture and animal models." Thesis, 2003. http://wwwlib.umi.com/cr/utexas/fullcit?p3118035.
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