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Characterization of a CHO cell line deficient in the folate-dependent trifunctional protein, MTHFDMascisch, Allegra January 1990 (has links)
No description available.
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Growth of a Bovine Mammary Epithelial Cell Line (Mac-T) on Cytodex 3 MicrocarriersRoper, Andrea M. January 1993 (has links)
No description available.
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CT1 and CT3 Mediated Apoptosis of MCF7 and SKBr3 Breast Cancer Cells via Extrinsic Apoptotic PathwayLocke, Autumn, Akinbote, Olasunkanmi, Harding, Jeanna, Torrenegra, Ruben, Bielski, Magdalena, Belcher, Dewey, Aramburo, Jacqueline, Hagood, Kendra Lyndsey, Hackworth, Keagan, Palau, Victoria 25 April 2023 (has links)
Breast cancer is the second most common cancer in women in the United States, accounting for approximately 30% of newly diagnosed female cancers every year. In 2023, it is estimated that around 297,790 invasive breast cancers will be diagnosed as new cases with nearly 43,700 women deaths. The average lifetime risk of a woman in the United States accruing a breast cancer diagnosis is approximately 13%, meaning that there is a 1 in 8 chance of developing breast cancer. Classification of breast cancers is distinguished based on the presence of three receptors: HER2, estrogen, and progesterone. Absence of these receptors is categorized as triple negative breast cancer and accounts for about 15% of all breast cancers, thus is the most aggressive and difficult to treat. In this study, research involving two flavonoids, CT1 and CT3 show cytotoxic effects against cell lines MCF7 (ER+, PR+, HER2-) and SKBr3 (ER-, PR-, HER2+), that represent the most common breast cancers. CT1 and CT3 were extracted from the leaves of Chromolaena tacotana using a Soxhlet extractor, followed by isolation and purification by chromatography. The cells were seeded and then treated with CT1 or CT3 at concentrations of 5, 10, 20, 40 and 80 mM for cytotoxicity assays, and 40mM for analysis of mechanism of action via immunoblotting and TUNEL. These two flavonoids differ on the presence of a double bond between positions 2 and 3. At the concentrations tested, CT1 has cytotoxic activity against MCF7 but no significant effect on SKBr3, while CT3 has cytotoxic activity against SKBr3 but not on MCF7. CT1 and CT3 target the activated forms of ERK, c-JUN and SP6; however, the effect of CT1 appears to be significantly stronger than CT3 and does not involve the survival pathway. CT1 and CT3 inhibit cell viability in MCF7 and SKBr3 breast cancer cells by activating an extrinsic apoptotic pathway. Additional studies using a triple negative breast cancer cell line has shown that this activation is independent of the presence of estrogen and progesterone receptors or the upregulation of HER2.
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Microarray analysis of drosophila EGF receptor signaling and cell line expression profilesButchar, Jonathan P. 13 March 2006 (has links)
No description available.
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Thymidylate synthase : development of a cell line with amplified genes and partial sequencing of the cDNA /Rossana, Cindylou Francine January 1984 (has links)
No description available.
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Isolation and characterization of cathepsin Z, a lysosomal cysteine proteinaseDeCourcy, Kristi R. 27 August 2007 (has links)
Cathepsin Z is a cysteine proteinase found in lysosomes of human cells. It was detected in human cultured cell lines using the peptidyl diazomethane inhibitor Fmoc-Leu-Leu- [¹²⁵]Tyr-CHN₂. The labeling of cathepsin Z by the inhibitor was both time- and concentration-dependent, and the proteinase was found in all human cell lines examined. The characteristics of cathepsin Z were examined in U-937 cells, a human monocytic line. The labeling of cathepsin Z was blocked by pre-incubation of the cells either in non-iodinated inhibitor or in the epoxysuccinyl peptide inhibitor E-64d, a specific inhibitor of cysteine proteinases. Cathepsin Z was not immunoprecipitated by antisera specific for cathepsins B, L, or S. Cathepsin Z has been estimated to be at millimolar concentrations in lysosomes, suggesting that it is a major lysosomal proteinase. The molecular weight of cathepsin Z was calculated to be 22.4 kDa by SDS-PAGE and 45— 47 kDa by native PAGE and gel exclusion chromatography, indicating that it is dimeric. Cathepsin Z is susceptible to digestion by endoglycosidase H, and oligosaccharides comprise 3.1 kDa of the reduced molecular weight. The expression of cathepsin Z was not affected by differentiation of U-937 cells with phorbol ester, unlike the expression of cathepsins B and S. Undifferentiated U-937 cells express low levels of cathepsins B and S; after differentiation, expression of cathepsins B and S is greatly increased. Cathepsin Z was purified from U-937 cells by anion exchange chromatography (Mono Q), affinity chromatography (concanavalin A), and preparatory electrophoresis. N-terminal sequence analysis of both the purified protein and fragments of the protein from a V8 digest indicates that cathepsin Z is a member of the papain superfamily of cysteine proteinases. / Ph. D.
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The Suspension Cultivation of, and the use of Alternative Cell lines for the In Vitro Cultivation of, Treponema Pallidum Subspecies PallidumRiley, Bryan Scott 05 1900 (has links)
This study had two objectives: to achieve suspension cultivation of Sf1Ep cells and to develop procedures for achieving the replication of T. pallidum in those cell cultures. Sf1Ep cells have been the sole cell line used for the in vitro cultivation of T. pallidum. A study was undertaken to determine if other cell lines can support growth of T. pallidum. Rabbit skin fibroblasts (RAB-9), nude mouse ear (NME) cells, and normal rebbit testis fibroblasts (RT) were compared to Sf1Ep cells for their ability to support in vitro multiplication of T. pallidum. RAB-9 cells supported multiplication of treponemes equal to that of Sf1Ep cells. NME and RT cells also supported growth but to a lesser extent than Sf1Ep cells. Utilization of alternative cell lines may lead to improved in vitro growth of T. pallidum including possible serial passage.
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Ibuprofen Nanoparticles and its cytotoxicity on A549 and HaCaT cell linesGraham, Stan, Phillip, Roy, Zahid, Myra, Bano, Nadia, Iqbal, Qasim, Mahboob, Fidaa, Chen, Xianfeng, Shang, Lijun January 2016 (has links)
Yes / Ibuprofen (IBF) is an outstanding non-steroidal drug for analgesic and anti-inflammatory therapies but
it exhibits poor solubility in water [1, 2]. Increased dosage administration has been linked to gastrointestinal and
cardiovascular complications [3]. Many techniques have been employed to improve the solubility of NSAIDs [4]. In this
study, the anti-solvent precipitation method was used to make Ibuprofen nanoparticles (IBF NPs). Optimised
preparation parameters such as solvent (ethanol), raw drug concentration (400 mg), solvent/anti-solvent ratio (1:50)
and surfactant concentration (0.25 mg/ml) have been studied to yield nanoparticles with a mean size of 58.8 nm,
which is confirmed by dynamic light scattering and transmission electron microscopy. These IBF NPs posess
increased aqueous solubility compared to the micro counterpart and maintain with chemical integrity indicated by high
performance liquid chromatography and Fourier transform infrared spectroscopy.
In addition, in vitro cytotoxicity of IBF NPs has been studied on A549 and HaCat cell lines using MTT and LDH
assays. Both cells were obtained from ATCC. The A549 cells were grown in a modification of Ham’s F-12, containing
L-glutamine, called F-12K. The HaCaT cells were grown in DMEM containing sodium pyruvate (110 mg/l). Normal cell
culture and sub-culture were applied and the cells were used after around 45 passages [5]. The cell culture media
containing 105cells/ml were placed in a 96-well plate with addition of IBF NPs and Micro form at concentrations in the
range of between 6 and 500 ug/ml by diluting them with DMEM and F-12K for use with the HaCaT and A549 cells
respectively. After 24, 48 and 72h exposure, the MTT and LDH cytotoxicity assay were performed in triplicates and on
three separate experiment cultures and the absorbance was recorded at 570 nm and 492nm respectively with Elisa
micro plate reader. The cell viability (%) related to control (cells in culture medium without NPs) was calculated. A very good cytotoxicity profile was observed, indicating an in vitro cytocompatibility of the IBF NPs in these cell culture
systems and no significant changes in cytotoxicity compared with Micro IBF.
We conclude that our IBF NPs have increased solubility, same chemical integrity and unchanged cytotoxicity
compared to IBF Micro drug. Further work will concentrate on optimising more rigorous parameter to produce
excellent quality NPs. More detailed characterisation of IBF NPs is to be tested, such as using PXRD and SEM to
further corroborate particle shape and size. The range of no toxic in vitro concentrations is also to be further
confirmed. Eventually scaled up preparation of IBF NPs will be developed without relinquishing NPs quality. This
would improve the potential for in vitro/ in vivo applications and clinical use of IBF NPs and NSAIDs in general.
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In vitro toxicity testing of phthalocyanines on different cell lines using a continuous laser sourceMaduray, Kaminee January 2010 (has links)
Submitted in fulfilment of the requirements of the Degree of Master of Technology: Biotechnology, Durban University of Technology, 2010. / Photodynamic therapy is a promising treatment for cancer. It involves the
combination of a photosensitizer and light of an appropriate wavelength (laser source)
to cause the destruction of cancer cells. Phthalocynanines are second–generation
photosensitizers with enhanced photophysical and photochemical properties.
In this in vitro study the effect of aluminium (AlTSPc) or zinc (ZnTSPc)
tetrasulfophthalocyanines in its inactive and active state (laser induced) on melanoma
(skin cancer cells), fibroblast (healthy normal skin cells) and keratinocyte (healthy
normal skin cells) cells was evaluated. For each of the cell lines approximately
3 x 104 cells/ml were seeded onto 24-well cell culture plates and allowed to attach
overnight, after which cells were treated with different concentrations of AlTSPc or
ZnTSPc. The photosensitizers were synthesized at Rhodes University. After 2 hrs,
cells were irradiated with a diode laser at a wavelength of 672 nm and a beam
diameter of 1 cm. The laser power varied between 20-30 mW and the irradiation time
was calculated to deliver a light dose of 4.5 J/cm2. Post-irradiated cells were
incubated for 24 hrs before cell viability was measured using the CellTiter-BlueTM
Viability Assay.
Also, the efficacy of the light dose and laser source used for the killing of
approximately 50% of the melanoma cancer cells were investigated. AlTSPc and
ZnTSPc decreased cell viability of melanoma cancer cells to approximately 50% with
photosensitizer concentrations of 40 μg/ml and 50 μg/ml respectively. These
photosensitizer concentrations caused a slight decrease in the percentage cell viability
of fibroblast and keratinocyte cells. Results for the dark toxicity assay showed that
iii
both photosensitizers in the presence of high concentrations (60 μg/ml – 100 μg/ml)
showed cytotoxicity effects on melanoma cancer cells in their inactive state. This was
not observed in fibroblast and keratinocyte cells treated under the same experimental
conditions. The optimal AlTSPc and ZnTSPc concentrations in combination with the
light dose of 4.5 J/cm2 was the most efficient in killing the melanoma cancer cells
with reduced killing effects on healthy normal fibroblast and keratinocyte cells when
compared to other light doses (2.5 J/cm2, 7.5 J/cm2 and 10 J/cm2).
The irradiation of cells photosensitized with the optimal photosensitizer
concentrations with a femtosecond laser using similar laser parameters to continuous
wave laser experiments resulted in a reduction in the cell viability of healthy normal
fibroblast and keratinocyte cells compared to melanoma cancer cells. The presence of
DNA degradation on agarose gel, morphological changes like blebbing and
ultrastructural changes like nucleus condensation indicated that photodynamic therapy
treated melanoma cancer cells with the optimal concentrations of AlTSPc and
ZnTSPc induced cell death via apoptosis. This concludes that low concentrations of
AlTSPc and ZnTSPc activated with an appropriate laser source can be used to induce
cell death in melanoma cancer cells. Both AlTSPc and ZnTSPc exhibit the potential to
be used as a photosensitizer in photodynamic therapy for the treatment of melanoma
cancer with the occurrence of minimal damage to surrounding healthy tissue.
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A study of genomic DNA methylation in immortalized human epithelial cell linesTse, Wan-wai, 謝韻慧 January 2008 (has links)
published_or_final_version / Anatomy / Master / Master of Philosophy
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