SEARCH · PubMed Health

Results for “Genetic Engineering”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 577 records · Page 32Linked to original sources

PubMed2006

Plant genetic engineering to improve biomass characteristics for biofuels.

Currently, most ethanol produced in the United States is derived from maize kernel, at levels in excess of four billion gallons per year. Plant lignocellulosic biomass is renewable, cheap and globally available at 10-50 billion tons per year. At present, plant biomass is converted to fermentable sugars for the production of biofuels using pretreatment processes that disrupt the lignocellulose and remove the lignin, thus allowing the access of microbial enzymes for cellulose deconstruction. Both the pretreatments and the production of enzymes in microbial tanks are expensive. Recent advances in plant genetic engineering could reduce biomass conversion costs by developing crop varieties with less lignin, crops that self-produce cellulase enzymes for cellulose degradation and ligninase enzymes for lignin degradation, or plants that have increased cellulose or an overall biomass yield.

Biomass↗

PubMed1996

Study on serum-free media for genetically engineered CHO cells producing prourokinase.

Based on the initial optimization of DMEM:F12(1:1), two kinds of serum-free media, 11G-SG-SFM and 11G-SE-SFM, were formulated by using orthogonal experiments for the growth of genetically engineered CHO cell line 11G and the production of recombinant prourokinase (pro-UK) in a suspension culture, respectively. Growth of 11G cells in 11G-SG-SFM was comparable with that observed in DMEM:F12 + 5% NBS and CHO-S-SFM. 11G cells grew slowly in 11G-SE-SFM, but secreted a relatively high level of pro-UK. The pro-UK productivity of 11G cells in 11G cells in 11G-SE-SFM reached 800 to 1,000 IU/10(6). d-1 and was about 80% and 20% higher than in DMEM:F12 + 5% NBS and CHO-S-SFM, respectively.

Animals↗

PubMed1999

[A new medical treatment for thrombosis by genetic engineering].

There has been established a new medical treatment that is due to the progress of genetic engineering and the development of gene delivery techniques. As well as other fields, cardiologists investigate a protocol for gene therapy, including thrombosis and its related diseases. They make steady progress in the application of clinical trials. Specially, they have focused on gene therapy for the restenosis after percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG), and there are many successful reports. As one of the strategy for an inhibition of thrombosis formation, they try to deliver the genes of cyclooxygenase-1, tissue plasminogen activator (tPA) and endothelial nitric oxide synthetase (eNOS). Also, we target for the introduction of anti-sense oligonucleotide; proliferating cell nuclear antigen (PCNA), cell division cycle (cdc)-2 kinase, or p21 (sdi-1) gene in order to inhibit the progression of cell cycle in which vascular smooth muscle cells (VSMCs). Others and we pay attention to the function of vessel protection and find a protocol for the gene delivery of vascular endothelial growth factor (VEGF) and hepatocyte growth factor (HGF), which selectively induce the growth of endothelial cell. Since, particularly, VEGF and HGF induce angiogenesis, Others and we try to cure arteriosclerosis obliterans (ASO) with delivering these genes to the affected part. In addition, we develop new techniques such as the delivery of NF kappa B gene toward myocardial infarction and the transplantation of genetically modified myocardium that is treated with gene therapy. We place our hopes on these new technical applications to the clinical trial.

Genetic Therapy↗

PubMed2006

Natural genetic transformation: A novel tool for efficient genetic engineering of the dairy bacterium Streptococcus thermophilus.

Streptococcus thermophilus is widely used for the manufacture of yoghurt and Swiss or Italian-type cheeses. These products have a market value of approximately 40 billion dollars per year, making S. thermophilus a species that has major economic importance. Even though the fermentation properties of this bacterium have been gradually improved by classical methods, there is great potential for further improvement through genetic engineering. Due to the recent publication of three complete genome sequences, it is now possible to use a rational approach for designing S. thermophilus starter strains with improved properties. Progress in this field, however, is hampered by a lack of genetic tools. Therefore, we developed a system, based on natural transformation, which makes genetic manipulations in S. thermophilus easy, rapid, and highly efficient. The efficiency of this novel tool should make it possible to construct food-grade mutants of S. thermophilus, opening up exciting new possibilities that should benefit consumers as well as the dairy industry.

DNA, Bacterial↗

PubMed1996

Assessment of the allergenic potential of foods derived from genetically engineered crop plants.

This article provides a science-based, decision tree approach to assess the allergenic concerns associated with the introduction of gene products into new plant varieties. The assessment focuses on the source from which the transferred gene was derived. Sources fall into three general categories: common allergenic food proteins; less common allergenic foods or other known allergen sources; and sources with no history of allergenicity. Information concerning the amino acid sequence identity to known allergenic proteins, in vitro and/or in vivo immunologic assays, and assessment of key physiochemical properties are included in reaching a recommendation on whether food derived from the genetically modified plant variety should be labeled as to the source of the transferred gene. In the end, a balanced judgement of all the available data generated during allergenicity assessment will assure the safety of foods derived from genetically engineered crops. Using the approaches described here, new plant varieties generated by genetic modification should be introduced into the marketplace with the same confidence that new plant varieties developed by traditional breeding have been introduced for decades.

Allergens↗

PubMed1996

Genetically engineered synthesis of natural products: from alkaloids to corrins.

Because many natural products are of biological and medicinal importance, methods are continually being sought for studying their biosynthetic pathways, which may eventually result in increased production and the generation of novel compounds. Advances in genetic engineering have enabled the homologous or heterologous expression of many natural product biosynthetic genes from divergent sources, resulting in a supply of enzymes not readily available by isolation from the producing organism. Mixing and matching of these enzymes in cell-free reactions can provide information, not available by any other means, about enzyme mechanisms, pathway intermediates, and possible variations in the structure of the final product.

Alkaloids↗

PubMed2001

Genetic engineering of a hypoallergenic trimer of the major birch pollen allergen Bet v 1.

An estimated 100 million individuals suffer from birch pollen allergy. Specific immunotherapy, the only curative allergy treatment, can cause life-threatening anaphylactic side effects. Here, we report the genetic engineering of a recombinant trimer consisting of three covalently linked copies of the major birch pollen allergen, Bet v 1. The trimer exhibited profoundly reduced allergenic activity but contained similar secondary structures such as Bet v 1 wild type, Bet v 1-specific B cell and T-cell epitopes, and induced Th1 cytokine release. As immunogen, rBet v 1 trimer induced IgG antibodies, which blocked patients' IgE binding to Bet v 1 and related allergens. Thus, rBet v 1 trimer represents a novel hypoallergenic vaccine prototype for treatment of one of the most frequent allergy forms.

Allergens↗

PubMed2001

Present status of modified hemoglobin as blood substitutes and oral therapy for end stage renal failure using artificial cells containing genetically engineered cells.

Artificial cell or bioencapsulation has been developed for use in bioartificial organs, drug delivery, blood substitutes, and other areas. Recent rapid advances in modified hemoglobin blood substitutes have resulted in advance stages of Phase III clinical trials. Another area of use is in oral therapy, using artificial cells microencapsulated with genetically engineered cells for use in end stage renal failure and other conditions.

Administration, Oral↗

PubMed1989

Genetic engineering of filamentous fungi.

Filamentous fungi are important in medicine, industry, agriculture, and basic biological research. For example, some fungal species are pathogenic to humans, whereas others produce beta-lactam antibiotics (penicillin and cephalosporin). Industrial strains produce large amounts of enzymes, such as glucoamylase and proteases, and low molecular weight compounds, such as citric acid. The largest and most economically important group of plant pathogens are fungi. Several fungal species have biological properties and genetic systems that make them ideally suited for basic biological research. Recently developed techniques for genetic engineering of filamentous fungi make it possible to alter their detrimental and beneficial activities in novel ways.

Aspergillus nidulans↗

PubMed1993

Enzyme-linked immunosorbent assay for an octapeptide based on a genetically engineered fusion protein.

Traditional chemical means of preparing enzyme-ligand conjugates for use in enzyme-linked immunosorbent assays (ELISAs) lead to the production of multisubstituted enzyme-ligand conjugates with a high degree of variability in the site of ligand attachment. A genetically engineered fusion protein was prepared in order to investigate the feasibility of controlled production of conjugates for use in ELISAs. Specifically, a synthetic octapeptide was fused with bacterial alkaline phosphatase. The resulting enzyme-peptide conjugate is monosubstituted (one peptide per subunit), has a single site of attachment, and results in assays with good response characteristics. The use of such fusion proteins, which combine small analyte peptides with enzyme labels, can lead to a new approach to improved assays for numerous biomolecules, including peptide pharmaceuticals, neurotransmitters, hormones, cell surface antigens, etc.

Alkaline Phosphatase↗

PubMed2004

[Advances in the research of genetic engineering of heavy metal resistance and accumulation in plants].

Using plants to remove or inactivate heavy metal pollutants from soils and surface waters provide a cheap and sustainable approach of Phytoremediation. However, field trials suggested that the efficiency of contaminant removal using natural hyperaccumulators is insufficient, due to that many of these species are slow growing and produce little shoot biomass. These factors severely constrain their potential for large-scale decontamination of polluted soils. Moreover, both the micronutrient and toxic metal content accumulated in crops determine the quality and safety of our food-chain. By a transgenic approach, the introduction of novel genes responsible for hyperaccumulating phenotype into high biomass plants and/or stable crops uptaking minerals as food is a promising strategy for the development of effective techniques of phytoremediation and improvement of nutritional value of stable food through a viable commercialization. Recently, the progress at molecular level for heavy metal uptaking, detoxification and hyperaccumulation in plants, and also the clarification of some functional genes in bacteria, yeasts, plants and animals, have advanced the research on genetic engineering plants of heavy metal resistance and accumulation, and on the functional genes (e . g. gsh1, MerA and ArsC) and their genetic transformated plants. These studies demonstrated commercialization potentials of phytoremediation. In this paper, the molecular approach, effects and problems in gene transformation were discussed in details, and also the strategy and emphases were probed into the future research.

Biodegradation, Environmental↗

PubMed1996

Techniques for genetic engineering in mycobacteria. Alternative host strains, DNA-transfer systems and vectors.

The study of mycobacterial genetics has experienced quick technical developments in the past ten years, despite a relatively slow start, caused by difficulties in accessing these recalcitrant species. The study of mycobacterial pathogenesis is important in the development of new ways of treating tuberculosis and leprosy, now that the emergence of antibiotic-resistant strains has reduced the effectiveness of current therapies. The tuberculosis vaccine strain M. bovis BCG might be used as a vector for multivalent vaccination. Also, non-pathogenic mycobacterial strains have many possible biotechnological applications. After giving a historical overview of methods and techniques, we will discuss recent developments in the search for alternative host strains and DNA transfer systems. Special attention will be given to the development of vectors and techniques for stabilizing foreign DNA in mycobacteria.

Cloning, Molecular↗

PubMed1983

A new technique for genetic engineering of Agrobacterium Ti plasmid.

A new technique is described that allows easy introduction of foreign genetic elements into specific regions of Agrobacterium tumefaciens DNA. It uses plasmids that (1) can be introduced, but not maintained in A. tumefaciens, (2) have a region homologous to the genome of the recipient, and (3) have an appropriate marker. Selection for the marker will yield transconjugants in which the introduced plasmid has recombined with the host genome. Applications of the technique are described.

Conjugation, Genetic↗

PubMed2004

Release of transforming plasmid DNA from actively growing genetically engineered Escherichia coli.

We studied the transforming ability of the extracellular plasmid DNA released from a genetically engineered Escherichia coli pEGFP and the culturing conditions for the release of transforming DNA. The transforming ability was evaluated by transformation of competent cells with filtrates of E. coli pEGFP cultures. The number of transformants increased with time when E. coli pEGFP cells grew exponentially in rich medium, but not in stationary phase or when inoculated in freshwater. These results suggested that crude extracellular plasmid DNA had transforming ability and this transforming DNA was mainly released by actively growing bacteria.

Colony Count, Microbial↗

PubMed2002

Genetically engineered silk-elastinlike protein polymers for controlled drug delivery.

The silk-elastinlike class of genetically engineered protein polymers is composed of tandemly repeated silk-like (Gly-Ala-Gly-Ala-Gly-Ser) and elastin-like (Gly-Val-Gly-Val-Pro) amino acid blocks. The precision with which these polymers can be synthesized, as well as the ability to incorporate motifs that allow for gel-formation, stimuli-sensitivity, biodegradation, and biorecognition have stimulated interest in their use for controlled drug and gene delivery. This review will focus on the synthesis and characterization of silk-elastinlike polymers as related to controlled drug delivery. The design and biological synthesis of the copolymers, by recombinant DNA techniques, are reviewed. The characterization of the polymers is discussed. Finally, biocompatibility of the polymers and recent studies to determine their potential utility for controlled drug and gene delivery are reviewed.

Bacterial Proteins↗

PubMed1999

Application of a floc-forming genetically engineered microorganism to a sequencing batch reactor for phenolic wastewater treatment.

For enhancing the survival of genetically engineered microorganisms (GEMs) in activated sludge processes, the use of a floc-forming bacterium as the host for a recombinant plasmid was proposed. The floc-forming and phenol-degrading GEM Sphingomonas paucimobilis 551 (pS10-45) was cultured to demonstrate this proposal. Although the maximum growth rate of the host strain S. paucimobilis 551 was low and the recombinant plasmid pS10-45 was unstable in the host, the resultant GEM S. paucimobilis 551 (pS10-45) was difficult to wash out together with the effluent, and it maintained population 3-4 times higher than the non-floc-forming GEM Escherichia coli HB101 (pS10-45) in a model activated sludge process operated in a sequencing batch mode. In the long run, the GEM-inoculated activated sludge process showed better phenol removal ability by the recombinant plasmid and better sludge settlement by the host strain.

Journal Article↗

PubMed1991

Effects of 2,4-dichlorophenol, a metabolite of a genetically engineered bacterium, and 2,4-dichlorophenoxyacetate on some microorganism-mediated ecological processes in soil.

A genetically engineered microorganism, Pseudomonas putida PPO301(pRO103), and the plasmidless parent strain, PPO301, were added at approximately 10 CFU/g of soil amended with 500 ppm of 2,4-dichlorophenoxyacetate (2,4-D) (500 mug/g). The degradation of 2,4-D and the accumulation of a single metabolite, identified by gas chromatography-mass spectrophotometry as 2,4-dichlorophenol (2,4-DCP), occurred only in soil inoculated with PPO301(pRO103), wherein 2,4-DCP accumulated to >70 ppm for 5 weeks and the concentration of 2,4-D was reduced to <100 ppm. Coincident with the accumulation of 2,4-DCP was a >400-fold decline in the numbers of fungal propagules and a marked reduction in the rate of CO(2) evolution, whereas 2,4-D did not depress either fungal propagules or respiration of the soil microbiota. 2,4-DCP did not appear to depress the numbers of total heterotrophic, sporeforming, or chitin-utilizing bacteria. In vitro and in situ assays conducted with 2,4-DCP and fungal isolates from the soil demonstrated that 2,4-DCP was toxic to fungal propagules at concentrations below those detected in the soil.

Journal Article↗

PubMed1999

Genetic engineering of plant lipids.

Vegetable oils are a major component of human diets, comprising as much as 25% of average caloric intake. Until recently, it was not possible to exert significant control over the chemical composition of vegetable oils derived from different plants. However, the advent of genetic engineering has provided novel opportunities to tailor the composition of plant-derived lipids so that they are optimized with respect to food functionality and human dietary needs. In order to exploit this new capability, it is essential for food scientists and nutritionists to define the lipid compositions that would be most desirable for various purposes.

Dietary Fats, Unsaturated↗