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Somatic structural rearrangements in genetically engineered mouse mammary tumors
Ignacio Varela, Christiaan Klijn, Phillip J Stephens, Laura J Mudie, Lucy Stebbings, Danushka Galappaththige, Hanneke van der Gulden, Eva Schut, Sjoerd Klarenbeek, Peter J Campbell, Lodewyk FA Wessels, Michael R Stratton, Jos Jonkers, P Andrew Futreal, David J Adams
Genome Biology , 2010, DOI: 10.1186/gb-2010-11-10-r100
Abstract: We show that although Brca1- and Brca2-deficient mouse mammary tumors have a defect in the homologous recombination pathway, there is no apparent difference in the type or frequency of somatic rearrangements found in these cancers when compared to other mouse mammary cancers, and tumors from all genetic backgrounds showed evidence of microhomology-mediated repair and non-homologous end-joining processes. Importantly, mouse mammary tumors were found to carry fewer structural rearrangements than human mammary cancers and expressed in-frame fusion genes. Like the fusion genes found in human mammary tumors, these were not recurrent. One mouse tumor was found to contain an internal deletion of exons of the Lrp1b gene, which led to a smaller in-frame transcript. We found internal in-frame deletions in the human ortholog of this gene in a significant number (4.2%) of human cancer cell lines.Paired-end sequencing of mouse mammary tumors revealed that they display significant heterogeneity in their profiles of somatic rearrangement but, importantly, fewer rearrangements than cognate human mammary tumors, probably because these cancers have been induced by strong driver mutations engineered into the mouse genome. Both human and mouse mammary cancers carry expressed fusion genes and conserved homozygous deletions.Cancers form in humans as a result of the accumulation of mutations that co-operate together in subversion of growth control and the cell death signals that would normally result in apoptosis. Somatic mutations in cancer genomes can be classified as those that contribute to the evolution of the cancer, so-called 'driver mutations', and 'passenger mutations' that can be used to reveal the signature of the underlying mutagenic process, but do not contribute to tumorigenesis. Generally, passenger mutations are thought to substantially outnumber driver mutations, meaning that functional validation is generally important to distinguish between these types of mutations. Thi
Hormone-induced protection of mammary tumorigenesis in genetically engineered mouse models
Lakshmanaswamy Rajkumar, Frances S Kittrell, Raphael C Guzman, Powel H Brown, Satyabrata Nandi, Daniel Medina
Breast Cancer Research , 2007, DOI: 10.1186/bcr1645
Abstract: Two mouse models, the p53-null mammary epithelial transplant and the c-neu mouse, were exposed to estrogen and progesterone for 2 and 3 weeks, respectively, and followed for development of mammary tumors.In the p53-null mammary transplant model, a 2-week exposure to estrogen and progesterone during the immediate post-pubertal stage (2 to 4 weeks after transplantation) of mammary development decreased mammary tumorigenesis by 70 to 88%. At 45 weeks after transplantation, analysis of whole mounts of the mammary outgrowths demonstrated the presence of premalignant hyperplasias in both control and hormone-treated glands, indicating that the hormone treatment strongly affects the rate of premalignant progression. One possible mechanism for the decrease in mammary tumorigenesis may be an altered proliferation activity as the bromodeoxyuridine labeling index was decreased by 85% in the mammary glands of hormone-treated mice. The same short-term exposure administered to mature mice at a time of premalignant development also decreased mammary tumorigenesis by 60%. A role for stroma and/or systemic mediated changes induced by the short-term hormone (estrogen/progesterone) treatment was demonstrated by an experiment in which the p53-null mammary epithelial cells were transplanted into the cleared mammary fat pads of previously treated mice. In such mice, the tumor-producing capabilities of the mammary cells were also decreased by 60% compared with the same cells transplanted into unexposed mice. In the second set of experiments using the activated Her-2/neu transgenic mouse model, short-term estradiol or estradiol plus progesterone treatment decreased mammary tumor incidence by 67% and 63%, and tumor multiplicity by 91% and 88%, respectively. The growth rate of tumors arising in the hormone-treated activated Her-2/neu mice was significantly lower than tumors arising in non-hormone treated mice.Because these experiments were performed in model systems that mimic many essential
Genetically-Engineered Pig-to-Baboon Liver Xenotransplantation: Histopathology of Xenografts and Native Organs  [PDF]
Burcin Ekser, Edwin Klein, Jing He, Donna B. Stolz, Gabriel J. Echeverri, Cassandra Long, Chih Che Lin, Mohamed Ezzelarab, Hidetaka Hara, Massimiliano Veroux, David Ayares, David K. C. Cooper, Bruno Gridelli
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0029720
Abstract: Orthotopic liver transplantation was carried out in baboons using wild-type (WT, n = 1) or genetically-engineered pigs (α1,3-galactosyltransferase gene-knockout, GTKO), n = 1; GTKO pigs transgenic for human CD46, n = 7) and a clinically-acceptable immunosuppressive regimen. Biopsies were obtained from the WT pig liver pre-Tx and at 30 min, 1, 2, 3, 4 and 5 h post-transplantation. Biopsies of genetically-engineered livers were obtained pre-Tx, 2 h after reperfusion and at necropsy (4–7 days after transplantation). Tissues were examined by light, confocal, and electron microscopy. All major native organs were also examined. The WT pig liver underwent hyperacute rejection. After genetically-engineered pig liver transplantation, hyperacute rejection did not occur. Survival was limited to 4–7 days due to repeated spontaneous bleeding in the liver and native organs (as a result of profound thrombocytopenia) which necessitated euthanasia. At 2 h, graft histology was largely normal. At necropsy, genetically-engineered pig livers showed hemorrhagic necrosis, platelet aggregation, platelet-fibrin thrombi, monocyte/macrophage margination mainly in liver sinusoids, and vascular endothelial cell hypertrophy, confirmed by confocal and electron microscopy. Immunohistochemistry showed minimal deposition of IgM, and almost absence of IgG, C3, C4d, C5b-9, and of a cellular infiltrate, suggesting that neither antibody- nor cell-mediated rejection played a major role.
Mammary pathology of the genetically engineered mouse
AD Borowsky
Breast Cancer Research , 2003, DOI: 10.1186/bcr670
Abstract:
Labeling of Genetically Engineered Foods:How University Student
Jennifer H. Schmidt,Charlene Hamilton
Journal of Food Technology , 2013,
Abstract: To assess and compare the perspectives of university students towards labeling of genetically engineered foods to that of a national opinion poll. Twenty-five question, multiple-choice survey, formatted into the university`s online course management system. Introductory nutrition class at a large Mid-Atlantic University. 39 students, ages 18-64. Student familiarity with, attitudes towards, and perceptions of labeling of genetically engineered foods. Frequencies, ANOVA, Cross-tabs, and t-tests. Signficance at p=0.05. An equivalent percentage of students compared to national opinion agreed that genetically engineered foods should be labeled. (66% versus 62% respectively). Comparison of the two data sets revealed only slight variability between the groups in specific areas. The student sample, gender approached significance (p=0.100) with females more in favor of labeling than males. These results suggest that further research is necessary in determining the expected effectiveness of labeling genetically engineered foods. A cost-benefit analysis should be conducted with consideration to the utilization of this information and of labeling in general by consumers. Further assessment of any effects a mandatory labeling system would have on the food supply and distribution system is needed. Education surrounding the entire process is imperative to consumer trust.
Significant Growth Inhibition of Canine Mammary Carcinoma Xenografts following Treatment with Oncolytic Vaccinia Virus GLV-1h68  [PDF]
Ivaylo Gentschev,Klaas Ehrig,Ulrike Donat,Michael Hess,Stephan Rudolph,Nanhai Chen,Yong A. Yu,Qian Zhang,J?rn Bullerdiek,Ingo Nolte,Jochen Stritzker,Aladar A. Szalay
Journal of Oncology , 2010, DOI: 10.1155/2010/736907
Abstract: Canine mammary carcinoma is a highly metastatic tumor that is poorly responsive to available treatment. Therefore, there is an urgent need to identify novel agents for therapy of this disease. Recently, we reported that the oncolytic vaccinia virus GLV-1h68 could be a useful tool for therapy of canine mammary adenoma in vivo. In this study we analyzed the therapeutic effect of GLV-1h68 against canine mammary carcinoma. Cell culture data demonstrated that GLV-1h68 efficiently infected and destroyed cells of the mammary carcinoma cell line MTH52c. Furthermore, after systemic administration, this attenuated vaccinia virus strain primarily replicated in canine tumor xenografts in nude mice. Finally, infection with GLV-1h68 led to strong inflammatory and oncolytic effects resulting in significant growth inhibition of the tumors. In summary, the data showed that the GLV-1h68 virus strain has promising potential for effective treatment of canine mammary carcinoma. 1. Introduction Malignant tumors of the mammary glands are among the most frequently observed tumors in female dogs [1–3]. Despite the success in diagnosis and treatment of mammary cancer, this disease entity remains one of the leading causes of cancer-related death in female dogs. Therefore, there is an urgent need to identify novel agents for therapy and diagnosis of mammary cancer. Among the most promising new therapeutic candidates are oncolytic viruses, which can target tumor tissue and specifically eradicate the cancer cells. This concept was already confirmed in human tumor xenograft treatment by the use of several viruses [4–9]. In the present study, we tested the recombinant oncolytic vaccinia virus GLV-1h68 as a therapeutic agent against canine mammary carcinoma. The GLV-1h68 virus strain was engineered by inserting expression cassettes encoding a Renilla luciferase-green fluorescent protein (GFP) fusion protein, -galactosidase, and -glucuronidase into the genome of the wild-type strain LIVP [10]. In nude mouse models, GLV-1h68 is highly attenuated compared to the wild-type strain [10]. We have already demonstrated that the injection of GLV-1h68 leads to regression and elimination of different tumor xenografts in nude mice [10–15]. More recently, we reported that GLV-1h68 could be a useful tool for therapy of canine mammary adenoma [12]. Here we describe that the GLV-1h68 virus successfully infected, replicated, and lysed canine mammary carcinoma MTH52c cells in cell culture. In addition, GLV-1h68 can efficiently prevent cancer growth in female nude mice with tumors derived from MTH52c
Biodegradation of azo dyes by genetically engineered azoreductase
WANG Jing,YAN Bin,ZHOU Ji-ti,BAO Yong-ming,LU Hong,YUAN Xiao-dong,
WANG Jing
,YAN Bin,ZHOU Ji-ti,BAO Yong-ming,LU Hong,YUAN Xiao-dong

环境科学学报(英文版) , 2005,
Abstract: A azoreductase gene with 537 bp was obtained by PCR amplification from Rhodobacter sphaeroides AS1 1737 The enzyme, with a molecular weight of 18 7 kD, was efficiently expressed in Escherichia coli and its biodegradation characteristics for azo dyes were investigated. Furthermore, the reaction kinetics and mechanism of azo dyes catalyzed by the genetically engineered azoreductase were studied in detail. The presence of a hydrazo-intermediate was identified, which provided a convincing evidence for the assumption that azo dyes were degraded via an incomplete reduction stage.
The Theory and Practice of Genetically Engineered Crops and Agricultural Sustainability
David E. Ervin,Leland L. Glenna,Raymond A. Jussaume
Sustainability , 2011, DOI: 10.3390/su3060847
Abstract: The development of genetically engineered (GE) crops has focused predominantly on enhancing conventional pest control approaches. Scientific assessments show that these GE crops generally deliver significant economic and some environmental benefits over their conventional crop alternatives. However, emerging evidence indicates that current GE crops will not foster sustainable cropping systems unless the negative environmental and social feedback effects are properly addressed. Moreover, GE crop innovations that promote more sustainable agricultural systems will receive underinvestment by seed and chemical companies that must understandably focus on private returns for major crops. Opportunities to promote crops that convey multi-faceted benefits for the environment and the poor are foundational to a sustainable food system and should not be neglected because they also represent global public goods. In this paper, we develop a set of criteria that can guide the development of GE crops consistent with contemporary sustainable agriculture theory and practice. Based on those principles, we offer policy options and recommendations for reforming public and private R&D and commercialization processes to further the potential contributions of GE crops to sustainable agriculture. Two strategies that would help achieve this goal would be to restore the centrality of the public sector in agricultural R&D and to open the technology development process to more democratic participation by farmers and other stakeholders.
Physicochemical characterization of two deproteinized bovine xenografts
Accorsi-Mendon?a, Thais;Conz, Márcio Baltazar;Barros, Teresa Cristina;Sena, Lídia ágata de;Soares, Glória de Almeida;Granjeiro, José Mauro;
Brazilian Oral Research , 2008, DOI: 10.1590/S1806-83242008000100002
Abstract: calcium phosphate salts, or more specifically hydroxyapatite, are products of great interest in the fields of medical and dental science due to their biocompatibility and osteoconduction property. deproteinized xenografts are primarily constituted of natural apatites, sintered or not. variations in the industrial process may affect physicochemical properties and, therefore, the biological outcome. the purpose of this work was to characterize the physical and chemical properties of deproteinized xenogenic biomaterials, bio-oss (geistlich biomaterials, wolhuser, switzerland) and gen-ox (baumer s.a., brazil), widely used as bone grafts. scanning electron microscopy, infrared region spectroscopy, x-ray diffraction, thermogravimetry and degradation analysis were conducted. the results show that both materials presented porous granules, composed of crystalline hydroxyapatite without apparent presence of other phases. bio-oss presented greater dissolution in tris-hcl than gen-ox in the degradation test, possibly due to the low crystallinity and the presence of organic residues. in conclusion, both commercial materials are hydroxyapatite compounds, bio-oss being less crystalline than gen-ox and, therefore, more prone to degradation.
Field Performance of a Genetically Engineered Strain of Pink Bollworm  [PDF]
Gregory S. Simmons, Andrew R. McKemey, Neil I. Morrison, Sinead O'Connell, Bruce E. Tabashnik, John Claus, Guoliang Fu, Guolei Tang, Mickey Sledge, Adam S. Walker, Caroline E. Phillips, Ernie D. Miller, Robert I. Rose, Robert T. Staten, Christl A. Donnelly, Luke Alphey
PLOS ONE , 2011, DOI: 10.1371/journal.pone.0024110
Abstract: Pest insects harm crops, livestock and human health, either directly or by acting as vectors of disease. The Sterile Insect Technique (SIT) – mass-release of sterile insects to mate with, and thereby control, their wild counterparts – has been used successfully for decades to control several pest species, including pink bollworm, a lepidopteran pest of cotton. Although it has been suggested that genetic engineering of pest insects provides potential improvements, there is uncertainty regarding its impact on their field performance. Discrimination between released and wild moths caught in monitoring traps is essential for estimating wild population levels. To address concerns about the reliability of current marking methods, we developed a genetically engineered strain of pink bollworm with a heritable fluorescent marker, to improve discrimination of sterile from wild moths. Here, we report the results of field trials showing that this engineered strain performed well under field conditions. Our data show that attributes critical to SIT in the field – ability to find a mate and to initiate copulation, as well as dispersal and persistence in the release area – were comparable between the genetically engineered strain and a standard strain. To our knowledge, these represent the first open-field experiments with a genetically engineered insect. The results described here provide encouragement for the genetic control of insect pests.
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