Academic literature on the topic 'Human cell culture - Effect of chemicals on'
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Journal articles on the topic "Human cell culture - Effect of chemicals on"
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KASAMAKI, Akiko, and Shozo URASAWA. "The effect of food chemicals on cell aging of human diploid cells in in vitro culture." Journal of Toxicological Sciences 18, no. 3 (1993): 143–53. http://dx.doi.org/10.2131/jts.18.3_143.
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Barile, Frank A., Dale Alexander, and Alicia Sookhoo. "Potential of Human Lung Cells for Predicting Acute Cytotoxicity." Alternatives to Laboratory Animals 23, no. 4 (July 1995): 461–68. http://dx.doi.org/10.1177/026119299502300407.
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— Human fetal lung fibroblasts (HFL1) were studied in culture to evaluate their potential as a screen for cytotoxicity. The cytotoxic concentrations determined in vitro were compared with established human and animal toxicity data. Confluent monolayers were incubated in the absence or presence of increasing concentrations of test chemicals for 24 hours, and the MTT assay was used to assess toxicity. Inhibitory concentrations were extrapolated from concentration-effect curves after linear regression analysis. Comparison of the cytotoxicity data with rodent lethal concentrations and human lethal concentrations obtained from the testing of 50 chemicals in human lung cells, suggests that the experimental IC50 values are as accurate as predictors of human toxicity as the equivalent toxic blood concentrations derived from rodent LD50 tests. In addition, evaluation of the first 15 chemicals reveals no significant differences between results from continuous cell lines of human and rodent origin. Together with a related battery of tests, cell culture procedures have the potential to supplement or replace current animal protocols in screening chemicals for human toxicity.
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Mannelli, C., F. Ietta, C. Carotenuto, R. Romagnoli, A. Z. Szostek, T. Wasniewski, D. J. Skarzynski, and Luana Paulesu. "Bisphenol A Altersβ-hCG and MIF Release by Human Placenta: AnIn VitroStudy to Understand the Role of Endometrial Cells." Mediators of Inflammation 2014 (2014): 1–11. http://dx.doi.org/10.1155/2014/635364.
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A proper fetomaternal immune-endocrine cross-talk in pregnancy is fundamental for reproductive success. This might be unbalanced by exposure to environmental chemicals, such as bisphenol A (BPA). As fetoplacental contamination with BPA originates from the maternal compartment, this study investigated the role of the endometrium in BPA effects on the placenta. To this end,in vitrodecidualized stromal cells were exposed to BPA 1 nM, and their conditioned medium (diluted 1 : 2) was used on chorionic villous explants from human placenta. Parallel cultures of placental explants were directly exposed to 0.5 nM BPA while, control cultures were exposed to the vehicle (EtOH 0.1%). After 24–48 h, culture medium from BPA-treated and control cultures was assayed for concentration of hormone human Chorionic Gonadotropin (β-hCG) and cytokine Macrophage Migration Inhibitory Factor (MIF). The results showed that direct exposure to BPA stimulated the release of both MIF andβ-hCG. These effects were abolished/diminished in placental cultures exposed to endometrial cell-conditioned medium. GM-MS analysis revealed that endometrial cells retain BPA, thus reducing the availability of this chemical for the placenta. The data obtained highlight the importance ofin vitromodels including the maternal component in reproducing the effects of environmental chemicals on human fetus/placenta.
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Hopkinson, Desirée, Rae Bourne, and Frank A. Barile. "In Vitro Cytotoxicity Testing: 24-hour and 72-hour Studies with Cultured Lung Cells." Alternatives to Laboratory Animals 21, no. 2 (April 1993): 167–72. http://dx.doi.org/10.1177/026119299302100208.
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This study was designed to evaluate the potential of an in vitro cell culture method for its ability to determine cytotoxicity and to compare the cytotoxic concentrations with established LD50 values for the same chemicals. Rat lung epithelial cells (L2) were incubated in the absence or presence of increasing concentrations of the test chemical for 24 hours, and the inhibition of incorporation of radio-labelled amino acids into newly synthesised proteins was used as a marker for toxicity. In addition, cultured cells were exposed to the test chemicals for 72 hours, and cell proliferation experiments were performed as parallel measures of toxicity. Inhibitory concentrations were extrapolated from concentration-effect curves after linear regression analysis. The biological significance of the results of testing 20 chemicals shows that the experimental IC50 values are as accurate as predictors of human toxicity as are equivalent toxic blood concentrations derived from rodent LD50s. Results obtained from 72-hour growth studies reveal a greater sensitivity to cytotoxicity than from the 24-hour protein synthesis experiments. Statistically, however, the differences between the two protocols are inconclusive. It is anticipated that these procedures, together with a related battery of tests, may supplement or replace animal protocols currently used for human risk assessment.
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Shibata, Michio, Takanari Tsuda, Hiroshi Itagaki, Shinobu Kato, Toshiaki Kobayashi, Hideyuki Ichikawa, and Yoshihiro Morikawa. "Interleukin-1α and Interleukin-8 Release by Human Keratinocyte Cell Culture Treated with Surfactants." Alternatives to Laboratory Animals 25, no. 2 (April 1997): 161–71. http://dx.doi.org/10.1177/026119299702500209.
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The effects of four cosmetic surfactants on interleukin (IL)-1α and IL-8 release from human keratinocytes were studied to investigate the feasibility of using these effects for the prediction of the irritation potential of chemicals. After exposure of cells to surfactants, the amounts of IL-1α and IL-8 released into culture medium were measured by ELISA. Cytotoxicity was evaluated by using the neutral red uptake (NRU) cytotoxicity assay. Cytokine release was increased 7–15 times by sodium lauryl sulphate (SLS), laurtrimonium chloride, cocamidopropyl betaine (CPB) and Oleth-5 at cytotoxic concentrations. IL-8 release was increased 3–4 times by SLS, CPB and Oleth-5 at subcytotoxic concentrations. After exposure to SLS, IL-1α was released within 1 hour, suggesting that IL-1α release is associated with membrane damage, whereas IL-8 release continued for 24 hours, suggesting that IL-8 was produced within the cells. Cytotoxicity tests and IL-8 release assays were also performed on seven other surfactants. The results show that moderate irritants CPB and PEG-4 dioleate, which have weak cytotoxic effects, significantly increased IL-8 release from human keratinocytes. It is suggested that measurement of IL-8 release is useful for predicting the irritation potential of chemicals which cannot be detected by using the NRU cytotoxicity assay.
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Dierickx, Paul J., Claudia Smit, and Ellen M. Scheers. "Cytotoxicity of the MEIC Reference Chemicals in Antioxidant-enriched Rat Hepatoma-derived Fa32 cells." Alternatives to Laboratory Animals 29, no. 3 (May 2001): 217–23. http://dx.doi.org/10.1177/026119290102900304.
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Since vitamin E increases the antioxidant status of cells, its influence on cytotoxicity was investigated. The neutral red uptake (NRU) inhibition effects of 39 MEIC reference chemicals were measured after treatment of rat hepatoma-derived Fa32 cells in the presence of vitamin E for 30 minutes. The results were quantified in terms of the NI50, the concentration of test compound required to reduce the NRU by 50%. Sodium chloride was the only chemical that was more toxic in the presence of vitamin E. This effect was related to the concentration of vitamin E in the cell culture medium. A vitamin E dose-related response was also observed for the decreased toxicity of paracetamol and caffeine. Glutathione levels were slightly increased in the presence of vitamin E, which could contribute to the protective effect of vitamin E. Of the remaining chemicals, 50% were less toxic in the presence of vitamin E, but the correlation with the acute human toxicity data of the MEIC study was not improved. The results imply that reactive oxygen species interfere with the toxicity of a high proportion of toxic chemicals. The assay described provides a quick and easy method for checking whether reactive oxygen species contribute to the toxicity of a chemical.
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Saavedra, Lorena, Kathleen Wallace, Theresa F. Freudenrich, Moritz Mall, William R. Mundy, Jorge Davila, Timothy J. Shafer, Marius Wernig, and Daniel Haag. "Comparison of Acute Effects of Neurotoxic Compounds on Network Activity in Human and Rodent Neural Cultures." Toxicological Sciences 180, no. 2 (February 4, 2021): 295–312. http://dx.doi.org/10.1093/toxsci/kfab008.
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Abstract Assessment of neuroactive effects of chemicals in cell-based assays remains challenging as complex functional tissue is required for biologically relevant readouts. Recent in vitro models using rodent primary neural cultures grown on multielectrode arrays allow quantitative measurements of neural network activity suitable for neurotoxicity screening. However, robust systems for testing effects on network function in human neural models are still lacking. The increasing number of differentiation protocols for generating neurons from human-induced pluripotent stem cells (hiPSCs) holds great potential to overcome the unavailability of human primary tissue and expedite cell-based assays. Yet, the variability in neuronal activity, prolonged ontogeny and rather immature stage of most neuronal cells derived by standard differentiation techniques greatly limit their utility for screening neurotoxic effects on human neural networks. Here, we used excitatory and inhibitory neurons, separately generated by direct reprogramming from hiPSCs, together with primary human astrocytes to establish highly functional cultures with defined cell ratios. Such neuron/glia cocultures exhibited pronounced neuronal activity and robust formation of synchronized network activity on multielectrode arrays, albeit with noticeable delay compared with primary rat cortical cultures. We further investigated acute changes of network activity in human neuron/glia cocultures and rat primary cortical cultures in response to compounds with known adverse neuroactive effects, including gamma amino butyric acid receptor antagonists and multiple pesticides. Importantly, we observed largely corresponding concentration-dependent effects on multiple neural network activity metrics using both neural culture types. These results demonstrate the utility of directly converted neuronal cells from hiPSCs for functional neurotoxicity screening of environmental chemicals.
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Walum, Erik, Elisabeth Hansson, and Alan L. Harvey. "In Vitro Testing of Neurotoxicity." Alternatives to Laboratory Animals 18, no. 1_part_1 (November 1990): 153–79. http://dx.doi.org/10.1177/026119299001800118.1.
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Many of the toxic compounds that are at large in the environment represent a risk to our neuronal functions. Chemicals may have a direct or indirect effect on the nervous system and they may interfere with general biochemical properties or specific neuronal structures and processes. In this review, a brief presentation of the major neurotoxicological targets is given, together with a discussion of some aspects of the use of different in vitro models for screening purposes and mechanistic studies. It is believed that in vitro methods offer special opportunities for the development of new neurotoxicological assays, and that this development will mainly involve cultured model systems. Therefore, a presentation of nerve and glia tissue culture methods is given, followed by an overview of how information on the action of mercury and mercurials, excitotoxins and acrylamide has been obtained through the use of cultured cell models. It is concluded that the developmental potential in cell neurotoxicology lies within the areas of separation and identification of cells representative for different structures in the nervous system, co-cultivation of different cell types, in vivo/in vitro (ex vivo) procedures, chemically defined media, metabolic competent cultures of human cells and improved physiological conditions for cultivation and exposure.
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Ponsoda, Xavier, Cristina Núñez, José Vicente Castell, and Maria José Gómez-Lechón. "Evaluation of the Cytotoxic Effects of MEIC Chemicals 31–50 on Primary Culture of Rat Hepatocytes and Hepatic and Non-hepatic Cell Lines." Alternatives to Laboratory Animals 25, no. 4 (July 1997): 423–36. http://dx.doi.org/10.1177/026119299702500405.
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The cytotoxicities of 20 chemicals (numbers 31–50) from the Multicenter Evaluation of In Vitro Cytotoxicity (MEIC) programme were assessed with a primary culture of rat hepatocytes and with two hepatic cell lines (Hep G2 and FaO) and one non-hepatic cell line (3T3). The cytotoxicities of the chemicals were evaluated by using the MTT test after the cells had been exposed to the chemicals for 24 hours. For a better evaluation of results, dose–response curves were mathematically linearised and cytotoxicity was expressed as IC50 values and IC10 values (the concentration causing 50% and 10% loss of cell viability, respectively). We found that all the compounds showed similar acute basal cytotoxicity in all four cellular systems (regardless of whether the cells were, or were not, metabolically competent or were or were not of human origin). When these results were used to predicit human toxicity in terms of a mathematical parameter (prediction error [PE]), we found that all four systems gave similar predictions of human toxicity. The best cytotoxicity parameter included in the PE calculation was the IC50/10, because of an underestimation of human toxicity by in vitro systems. However, when PEs were calculated for rodent toxicity, better results were obtained. Data from the literature obtained by using other experimental models for predicting human toxicity were analysed according to the same criteria. We conclude that cellular systems are better predictive tools for human toxicity than are prokaryotic cells or whole-organism models.
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Nishino, Taito, Takumi Mikashima, Makiko Yui, Yasuyuki Asai, Hiromitsu Nakauchi, and Atsushi Iwama. "A Chemical Approach for Ex Vivo Expansion of Human Hematopoietic Stem Cells." Blood 118, no. 21 (November 18, 2011): 481. http://dx.doi.org/10.1182/blood.v118.21.481.481.
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Abstract Abstract 481 Hematopoietic stem cells (HSCs) have been applied to treatment of a wide variety of malignant and non-malignant blood disorders. Because of low risk of graft versus-host disease, use of human cord blood (hCB) as a source of HSCs continues to increase. However, wide application of hCB is limited by the relatively low number of HSCs obtained from a single CB unit. Numerous attempts have been made to expand hCB HSCs in cultures to acquire a sufficient number of transplantable HSCs. Chemical approaches have especially showed promise for ex vivo expansion of HSCs. As an example, Boitano et al. reported that SR1, a chemically synthesized purine derivative, induced hCB HSC expansion by antagonizing the aryl hydrocarbon receptor. In this study, we initially screened several tens of thousands of small-molecule compounds for the capability to induce STAT5 activation but obtained active compounds showed no positive effect on proliferation of hCB CD34+ hematopoietic stem and progenitor cells (HSPCs). However, a derivative of the STAT5 activating compounds proved to increase the population of CD34+CD38– cells when added to hCB CD34+ cell culture. Thus, we optimized the chemical structure of the compound and identified MISK303 as the most potent compound. We next evaluated the effects of MISK303 on the ex vivo expansion of hCB CD34+ cells in detail; hCB CD34+ cells were cultured in serum-free medium supplemented with MISK303 in addition to rhTPO and rhSCF for 7 days and analyzed the cellular phenotype of the cultured cells by flow cytometry and colony assays. Although the total and CD34+ cell number when cultured with MISK303 was comparable to that cultured with DMSO (vehicle), the cultures with MISK303 exhibited a >2-fold increase in the number of CD34+CD38– cells and contained 1.7-fold more high proliferative potential colony-forming cells (HPP-CFCs; >1mm in diameter) compared to those with DMSO. Correspondingly, in the NOD/SCID repopulation assay, hCB CD34+ cells cultured with MISK303 for 7 days displayed up to 2-fold higher levels of engraftment compared to control cultures and uncultured HSPCs. These data suggest that MISK303 promotes the net expansion of hematopoietic stem and progenitor cells. Furthermore, combination of SR1 and MISK303 had additive effects; cell cultures with SR1 and MISK303 showed a >4-fold increase in the number of CD34+CD38– cells. In accordance with the data, MISK303 had no antagonizing activity against the aryl hydrocarbon receptor. We also observed that a chemically-synthesized TPO receptor (c-mpl) agonist could be substituted with rhTPO and provided better expansion of CD34+CD38– cells in combination with SR1 and MISK303. To investigate the molecular mechanism by which MISK303 increases HSPCs, we first conducted gene expression profiling of CD34+ cells cultured with MK303 by DNA microarray analysis. Treatment of CD34+ cells with MISK303 for 24 hours led to up-regulation of 343-genes (>2-fold) and down-regulation of 112 genes (<0.5-fold). We also profiled effect of MISK303 over 311 protein kinases and found no inhibitory activity. We are now validating the expression of differentially expressed genes identified by DNA microarray analysis. In conclusion, we have conducted high-throughput screening and identified MK303, a novel chemically synthesized small-molecule compound, which induces the expansion of human HSCs ex vivo. The approach using MISK303 will facilitate the development of novel and efficient technologies for hematopoietic stem cell and gene therapies. Disclosures: No relevant conflicts of interest to declare.
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.
Books on the topic "Human cell culture - Effect of chemicals on"
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Rogiers, Vera, Walter Sonck, and Elizabeth Shephard. Human Cells in in Vitro Pharmaco-Toxicology: Present Status Within Europe. Vub Brussels University Press, 1994.
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Human cells in in vitro pharmaco-toxicology: Present status within Europe. Brussels: Vubpress, 1993.
Find full textBook chapters on the topic "Human cell culture - Effect of chemicals on"
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Shelikoff, Marc, A. J. Sinskey, and Gregory Stephanopoulos. "The effect of protein synthesis inhibitors on the glycosylation site occupancy of recombinant human prolactin." In Cell Culture Engineering IV, 195–208. Dordrecht: Springer Netherlands, 1994. http://dx.doi.org/10.1007/978-94-011-0257-5_22.
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Theilig, C., A. Bernd, F. E. Görmar, A. Ramirez-Bosca, J. Bereiter-Hahn, B. Keller-Stanislawski, N. Rietbrock, and H. Holzmann. "Effect of Nicotine on the Differentiation of Human Keratinocytes In Vitro." In Cell and Tissue Culture Models in Dermatological Research, 315–23. Berlin, Heidelberg: Springer Berlin Heidelberg, 1993. http://dx.doi.org/10.1007/978-3-642-77817-9_35.
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Watt, Fiona M. "Effect of Culture Environment on Terminal Differentiation of Human Epidermal Keratinocytes." In Pharmaceutical Applications of Cell and Tissue Culture to Drug Transport, 271–81. Boston, MA: Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4757-0286-6_22.
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Pellis, Neal R., Alexander Chouker, B. Yic, Svantje Tauber, Oliver Ullrich, and A. Sundaresan. "Overview and Translational Impact of Space Cell Biology Research." In Effect of Spaceflight and Spaceflight Analogue Culture on Human and Microbial Cells, 3–37. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3277-1_1.
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Zaritskey, A. Y., and O. V. Strizhak. "The Effect of Bone Marrow Fibroblast and Stromal Cell-Conditioned Media on Hemopoietic Cells in Culture." In Modern Trends in Human Leukemia IX, 101–5. Berlin, Heidelberg: Springer Berlin Heidelberg, 1992. http://dx.doi.org/10.1007/978-3-642-76829-3_19.
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Kontogiannatos, Dimitrios, Anna Kolliopoulou, and Luc Swevers. "The 'Trojan horse' approach for successful RNA interference in insects." In RNAi for plant improvement and protection, 25–39. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789248890.0025.
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Abstract Since the discovery of RNA interference in 1998 as a potent molecular tool for the selective downregulation of gene expression in almost all eukaryotes, increasing research is being performed in order to discover applications that are useful for the pharmaceutical and chemical industry. The ease of use of double-stranded RNA for targeted in vivo gene silencing in animal cells and tissues gave birth to a massive interest from industry in order to discover biotechnological applications for human health and plant protection. For insects, RNAi became the 'Holy Grail' of pesticide manufacturing, because this technology is a promising species-specific environmentally friendly approach to killing natural enemies of cultured plants and farmed animals. The general idea to use RNAi as a pest-control agent originated with the realization that dsRNAs that target developmentally or physiologically important insect genes can cause lethal phenotypes as a result of the specific gene downregulation. Most importantly to achieve this, dsRNA is not required to be constitutively expressed via a transgene in the targeted insect but it can be administrated orally after direct spraying on the infested plants. Similarly, dsRNAs can be administered to pests after constitutive expression as a hairpin in plants or bacteria via stable transgenesis. Ideally, this technology could have already been applied in integrated pest management (IPM) if improvements were not essential in order to achieve higher insecticidal effects. There are many limitations that decrease RNAi efficiency in insects, which arise from the biochemical nature of the insect gut as well as from deficiencies in the RNAi core machinery, a common phenomenon mostly observed in lepidopteran species. To overcome these obstacles, new technologies should be assessed to ascertain that the dsRNA will be transferred intact, stable and in high amounts to the targeted insect cells. In this chapter we will review a wide range of recent discoveries that address the delivery issues of dsRNAs in insect cells, with a focus on the most prominent and efficient technologies. We will also review the upcoming and novel use of viral molecular components for the successful and efficient delivery of dsRNA to the insect cell.
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Kontogiannatos, Dimitrios, Anna Kolliopoulou, and Luc Swevers. "The 'Trojan horse' approach for successful RNA interference in insects." In RNAi for plant improvement and protection, 25–39. Wallingford: CABI, 2021. http://dx.doi.org/10.1079/9781789248890.0004a.
Full textAbstract:
Abstract Since the discovery of RNA interference in 1998 as a potent molecular tool for the selective downregulation of gene expression in almost all eukaryotes, increasing research is being performed in order to discover applications that are useful for the pharmaceutical and chemical industry. The ease of use of double-stranded RNA for targeted in vivo gene silencing in animal cells and tissues gave birth to a massive interest from industry in order to discover biotechnological applications for human health and plant protection. For insects, RNAi became the 'Holy Grail' of pesticide manufacturing, because this technology is a promising species-specific environmentally friendly approach to killing natural enemies of cultured plants and farmed animals. The general idea to use RNAi as a pest-control agent originated with the realization that dsRNAs that target developmentally or physiologically important insect genes can cause lethal phenotypes as a result of the specific gene downregulation. Most importantly to achieve this, dsRNA is not required to be constitutively expressed via a transgene in the targeted insect but it can be administrated orally after direct spraying on the infested plants. Similarly, dsRNAs can be administered to pests after constitutive expression as a hairpin in plants or bacteria via stable transgenesis. Ideally, this technology could have already been applied in integrated pest management (IPM) if improvements were not essential in order to achieve higher insecticidal effects. There are many limitations that decrease RNAi efficiency in insects, which arise from the biochemical nature of the insect gut as well as from deficiencies in the RNAi core machinery, a common phenomenon mostly observed in lepidopteran species. To overcome these obstacles, new technologies should be assessed to ascertain that the dsRNA will be transferred intact, stable and in high amounts to the targeted insect cells. In this chapter we will review a wide range of recent discoveries that address the delivery issues of dsRNAs in insect cells, with a focus on the most prominent and efficient technologies. We will also review the upcoming and novel use of viral molecular components for the successful and efficient delivery of dsRNA to the insect cell.
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Tauber, Svantje, Buqing Yi, Alexander Choukèr, and Oliver Ullrich. "Use of In Vitro Cell Culture Models to Understand the Cellular and Molecular Basis of Immune Dysfunction During Spaceflight." In Effect of Spaceflight and Spaceflight Analogue Culture on Human and Microbial Cells, 121–29. New York, NY: Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4939-3277-1_6.
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Okumura, Noriko, Takafumi Yoshikawa, Jin Iida, Akitaka Nonomura, and Yoshinori Takakura. "Osteogenic Effect of Genistein on In Vitro Bone Formation by Human Bone Marrow Cell Culture - For Development of Advanced Bio-Artificial Bone." In Bioceramics 17, 667–70. Stafa: Trans Tech Publications Ltd., 2005. http://dx.doi.org/10.4028/0-87849-961-x.667.
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Beaupain, R., M. C. Martyré, and E. Falcoff. "The organotype culture model of human cancer cells: the effect of human recombinant interferons." In Modern Approaches to Animal Cell Technology, 662–81. Elsevier, 1987. http://dx.doi.org/10.1016/b978-0-408-02732-8.50054-7.
Full textConference papers on the topic "Human cell culture - Effect of chemicals on"
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Baker, Brendon M., Amy M. Silverstein, and Robert L. Mauck. "Engineering Dense Connective Tissues via Anisotropic Nanofibrous Scaffolds With High Sacrificial Fiber Content." In ASME 2010 First Global Congress on NanoEngineering for Medicine and Biology. ASMEDC, 2010. http://dx.doi.org/10.1115/nemb2010-13371.
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Given their ability to dictate initial cell alignment and subsequent matrix organization, aligned electrospun scaffolds are a fitting means for engineering fiber-reinforced, anisotropic tissues such as tendon, ligament, the knee meniscus, and the annulus fibrosus [1–4]. However, one commonly observed limitation of such scaffolds is the relatively slow infiltration rates of surface-seeded cells, where the central thicknesses of constructs cultured for 10 weeks remain devoid of cells [3]. This limitation arises from the tight packing of fibers which yields small pore sizes, thereby hampering cell migration. Towards accelerating cell ingress, we have recently reported on two-polymer composite scaffolds containing both slow eroding poly(ε-caprolactone) (PCL) fibers as well as water-soluble poly(ethylene oxide) (PEO) fibers that serve as space holders during scaffold formation [5]. Removal of these PEO fibers prior to seeding resulted in improved cell infiltration after 3 weeks, but the long-term maturation of such constructs has yet to be characterized. To assess the effect of sacrificial PEO fiber content on construct growth, a triple-jet electrospinning device was employed to generate PCL/PEO scaffolds with PEO fiber fractions ranging from 0 to 60%. After seeding with human meniscus fibrochondrocytes (hMFCs), constructs were clamped in custom grips to maintain strip morphology. The mechanical and biochemical maturation of constructs was assessed over 12 weeks of free swelling culture in a chemically defined medium (CDM), along with cell infiltration and matrix distribution. We hypothesized that enhanced pore size in dual-fiber constructs would lead to not only to a better distribution of cells, but also to larger increases in stiffness resulting from enhanced matrix production and distribution.
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Tsao, Chia-Wen, Meng-Zhi Chiang, and Yu-Che Cheng. "Effects of Chemical and Physical Shear-Stress Stimulation of Human Placenta-Derived Multipotent Stem Cells in Microchannel." In ASME 2013 11th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/icnmm2013-73194.
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Multipotent cells obtain from human postpartum term placenta is an ethically conductive, easily accessible and high-yielding stem cell source. In this conference presentation, we demonstrate using microchannel platform to culture and differentiate the human placenta-derived stem cells. Both chemical and shear stress stimulation effects were investigated.
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Ikeda, Yutaka, Tomoki Yoshinari, and Yukio Nagasaki. "Impact of ROS scavenging effect on cell culture and bio assembler." In 2014 International Symposium on Micro-NanoMechatronics and Human Science (MHS). IEEE, 2014. http://dx.doi.org/10.1109/mhs.2014.7006086.
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Nakashima, Yuta, Kohichi Tsusu, Yuki Hikichi, Tairo Yokokura, Kazuyuki Minami, and Yoshitaka Nakanishi. "Evaluation of cell-cell or cell-substrate adhesion effect on cellular differentiation using a microwell array having convertible culture surface." In 2014 International Symposium on Micro-NanoMechatronics and Human Science (MHS). IEEE, 2014. http://dx.doi.org/10.1109/mhs.2014.7006132.
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Gupta, M. S., and S. B. Nicoll. "Lower Macromer Concentration Enhances Nucleus Pulposus-Like Differentiation and Functional Extracellular Matrix Assembly by Human Marrow-Derived Stromal Cells Encapsulated in Photocrosslinked Carboxymethylcellulose Hydrogels." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80697.
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Intervertebral disc (IVD) degeneration is associated with dehydration and loss of integrity of the nucleus pulposus (NP) region of the disc. The NP is a tissue comprised mainly of proteoglycans and type II collagen (COL II) [1]. Tissue engineering therapies could provide viable NP replacements as an alternative to current surgical procedures. Recently, photocrosslinked carboxymethylcellulose (CMC) hydrogels were shown to support cell viability and the assembly of functional extracellular matrix (ECM) by encapsulated human marrow-derived mesenchymal stromal cells (hMSCs) when cultured in serum-free, chemically defined medium with TGF-β3 [2]. Previous studies have shown that scaffold macromer density can influence functional mechanical properties and chondrogenic differentiation of several cells types in various hydrogel systems [3,4,5]. However, the impact of macromer concentration on hMSC differentiation in CMC hydrogels has not been evaluated. Therefore, the objective of this study was to examine the effects of CMC macromer concentration on NP-like differentiation and the elaboration of functional ECM in hMSC-laden CMC constructs.
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Khalid, Muhammad, Chenn Zhou, Ashish Bassi, San Ming Wang, Howard Gerber, and Charles Tseng. "Heat Transfer Analysis of Human Cell Culture Under RF Exposure." In ASME 2005 Summer Heat Transfer Conference collocated with the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems. ASMEDC, 2005. http://dx.doi.org/10.1115/ht2005-72655.
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A 2.45 GHz radio frequency (RF) exposure system was designed and used to study the RF effects on the genome-wide gene expression in cultured human cells. In this system, a T-25 culture flask, which contains 10 × 106 cells in a 10ml medium, is placed in a WR 340 waveguide. The waveguide serves as an environmental chamber. The source is a pulsed magnetron for obtaining a high electric field with the specific absorption rate (SAR) at approximately 10 W/kg. In order to ensure the non-thermal effect, the system was designed to maintain a temperature of 37°C. In this research, the heat transfer analysis of the system was conducted using the computational fluid dynamic (CFD) software FLUENT® coupled with the finite element software, High Frequency Structural Simulation (HFSS) by Ansoft. The electric field was first analyzed by using HFSS to calculate the SAR distribution as a heat source input for CFD calculations. The fluid flow and temperature distributions within the flask were then analyzed using FLUENT®. The results were validated experimentally by measuring the temperatures with fluoroptic thermometer probes as well as by examining the level of heat shock gene expression. These results provide useful information for a better understanding and controlling of the operating conditions of the system.
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BOUTHERIN-FALSON, O., and N. BLAES. "EFFECT OF NICOTINE ON HUMAN UMBILICAL VEIN ENDOTHELIAL CELLS IN CULTURE : PROSTACYCLIN PRODUCTION AND PROLIFERATION STUDIES." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1643378.
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Clinical observations and results from animal studies indicate that nicotine may play a role in vascular disorders related to smoking. It has been reported that nicotine could alter vascular prostacyclin (PGI2) production and increase the number of circulating endothelial cells. In the present study, the direct effect of nicotine on endothelial cells in culture was investigated : Both PGI2 production and proliferative abilities were studied.PGI2 production studies : human umbilical vein endothelial cells (HUVEC) were grown in 4 days to confluency in control medium (RPM/199 1:1 + 20% fetal calf serum). At the beginning of the experiments, medium was replaced by tyrode Hepes buffer added or not with nicotine at different concentrations (0.05,0.5, 5, 50 or 200 ug/ml). Basal production of PGI2, assessed after 20 minutes, was significantly increased by 0.5 ug/ml nicotine (223% of control) ; subsequently thrombin (1 U/ml) stimulated release was measured after 5 minutes, it was dose dependently decreased by nicotine. Thus, at least in basal conditions, nicotine treatment of HUVEC alone in culture did not permit us to reproduce the inhibitory effects described on models involving smooth muscle cells in addition to the endothelial cells. Otherwise, nicotine could interfere with stimulating agents such as thrombin. Investigations on the effect of these agents in combination are currently in progressProliferation studies : Cells were grown in nicotine or control medium. Proliferation ability, estimated by the increase in cell number at daily interval was slighly increased in cultures receiving 0.05 ug/ml nicotine (110.4% of control). This tendancy was confirmed by 3H Thymidine incorporation (+41%). On the contrary a decrease in cell density was observed for the highest concentrations, from 50 ug/ml. This later effect did not seem to be related to any cytotoxicity or cell detachment. Thus, endothelial cells appeared to be highly responsive to nicotine in their PGI2 production while their growth characteristics were rather resistant to nicotine treatment.
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Honda, T., M. Aosaki, T. Tanaka, M. Aosaki, T. Uchida, S. Kimata, K. Hirosawa, Y. Horikawa, S. Ishizuka, and K. Ohki. "EFFECTS OF INTRAVENOUS ADMINISTRATIONOF A TISSUE-TYPE PLASMINOGEN ACTIVATOR (AK-124) IN ACUTE MYOCARDIAL INFARCTION, INCLUDING CHANGES IN BLOOD COAGULATION AND FIBRINOLYTIC ACTIVITY.- PRELIMINARY REPORT." In XIth International Congress on Thrombosis and Haemostasis. Schattauer GmbH, 1987. http://dx.doi.org/10.1055/s-0038-1644894.
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We administered a tissue-type plasminogen activator (t-PA) intravenously to 10 patients with acute myocardial infarction (AMI), within 6 hours after the onset of symptoms, and then examined the state of reperfusion by coronary arterio graphy (CAG), and observed changes in blood coagulation and fibrinolytic activity to evaluate the drug effects. AK-124 (produced by Asahi Chemical Industry and Kowa Co., Ltd.in collaboration), a t-PA produced the by tissue cultureof normal human lung cells, was given in a dosage of48,000_576,000 A.K. units by intravenous infusionover 30_45 minutes. In 7 patients who received t-PA, areflow or improved flow was detected on CAG. In t-PAtreated patients, euglobulin lysis activity clearly increased, euglobulin lysis time clearly shortened, and D-dimer increased. After t-PA treatment, the levels of circulating fibrinogen and a2-plasmin inhibitor decreased by an average of 12%, and 14% of base-line values respectively, but plasminogen showed no detectable change. A hematoma at the site of the catheter insertion was observed in one patient. These observations suggest that t-PA has a higher specificity for fibrin bound plasminogen than for plasma plasminogen, and produces coronary thrombolysis without causing systemic fibrinolysis, at least with the above dosage.
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Kumar, Arun, and Binil Starly. "Modeling Human Mesenchymal Stem Cell Expansion in Vertical Wheel Bioreactors Using Lactate Production Rate in Regenerative Medicine Biomanufacturing." In ASME 2016 11th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/msec2016-8787.
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Stem cells are critical components of regenerative medicine therapy. However, the therapy will require millions to billions of therapeutic stem cells. To address the need, we have recently cultured stem cells in 3D microgels and used them as a vehicle for cell expansion within a low shear stress rotating wheel type bioreactor within a 500ml volumetric setting. This study specifically highlights the cell encapsulation in microbead process, harvesting and operation of microbeads within a dynamic bioreactor environment. We have specifically encapsulated stem cells (human adipose derived) into microbeads prepared from alginate hydrogels via an electrostatic jetting process. This study highlights the effect of fabrication process parameters on end-point biological quality measures such as stem cell count and viability. We were able to maintain a >80% viability during the 21 day static culture period. We have also measured the concentration of metabolites produced during the expansion, specifically lactate production measured during specific time points within culture inside the rotating wheel bioreactor Future work will need to address predicting yields in higher volume settings, efficiency of harvest and a more detailed description of the hydrodynamics affecting stem cell growth.
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Herndon, Marcus. "Effect of Thermal Depolymerization of Wasted Food Extracts on Alternate Fuel Production." In ASME 2016 10th International Conference on Energy Sustainability collocated with the ASME 2016 Power Conference and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/es2016-59535.
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Human activities like fossil fuel retrieval, biomass burning, waste disposal, and residential and commercial use of energy are continuing to effect the Earth’s energy budget by changing the emissions and resulting atmospheric concentrations of radioactively important gases, aerosols, and by changing land surface properties. These activities negatively contribute to Earth’s greenhouse gases including water vapor (H2O), carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and ozone (O3). Approximately 82% of greenhouse gases are developed from the United States, Asia, and Europe alone. Food and their extraction processes, including transportation of those extracts, account for about 35% of those greenhouse gases. This includes wasted, rotten, and uneaten food. About 40% of food in the United States today goes uneaten, resulting in more than 20 pounds of food per person every month. Not only does this mean that Americans are throwing out upwards of $165 billion each year, amounting to $1,350 to more than $2,275 annually in waste per family of four, but also 25 percent of all freshwater and huge amounts of unnecessary chemicals, energy, and land. Moreover, almost all of that uneaten food ends up rotting in landfills. This number has increased, in regards to organic matter, from approximately 16 percent of U.S. methane emissions in 2010 upwards to 25 percent in 2012. With the increase in supply and demand of food, in addition to the lower consumer cost, the statistics of wasted feedstocks are rapidly increasing. The purpose of this research is to utilize wasted food to extract natural hydrocarbon oils through thermal depolymerization in order to develop an alternative fuel. Thermal depolymerization is a hydrous pyrolysis process that breaks down long chained polymers into simpler compounds and light hydrocarbons, much of which can be separated and used for fuel. Polymers include essentially all organic matter i.e. matter made of living or once-living things, which include petroleum products like plastic, styro-foam, and nylon, as well as plant and animal material, and manure. Potatoes and corn starch were used as feedstocks for this research and thermal depolymerization was conducted on the feedstocks for analysis and fuel collection. With optimum use and a mature thermal depolymerization technology, the Earth might comfortably support 10 times its current population at a high standard of living. There is enough biomass existing now accessible on the surface of the earth to provide 100 years of human energy use.