What methods based on DNA technology are used for detecting infectious diseases, such as AIDS, tuberculosis, Lyme disease, and human papilloma virus infection?
DNA methods such as Polymerase Chain Reaction, also known as PCR amplification techniques are used to be able to derive the the DNA and RNA signature of pathogens, therefore making the process of detecting microbes more efficient. Also, a special approach to detecting pathogens is called Quantitive Polymerase Chain Reaction (qPCR). The nucleic acid sequence of the pathogen is used to construct olives to swiftly and efficiently detect the specific pathogen.
Source: http://www.premierbiosoft.com/tech_notes/pathogen-detection.html
How is DNA analysis used to detect genetic diseases, such as cystic fibrosis, Duchenne’s muscular dystrophy, and Huntington’s disease?
DNA analysis, in the form of Gene Tests detect genetic disorders by examining the DNA sample taken from an individual and examining its mutations. This is done through the help of probes, which are complements of mutated sequences, which bind to the mutated strip of DNA, therefore detecting the possible genetic complication or disease. These tests include carrier screening, new born and pre natal testing, presymptomatic testing for adult-onset disorders such as Huntington's disease, and identifying an individual.
Source: http://www.ornl.gov/sci/techresources/Human_Genome/medicine/genetest.shtml
Pharmaceutical products. Gene defects in humans can lead to deficiencies in proteins such as insulin, human growth hormone, and Factor VIII. These protein deficiencies may lead to problems such as diabetes, dwarfism, and impaired blood clotting, respectively. Missing proteins can now be replaced by proteins manufactured through biotechnology. For insulin production, two protein chains are encoded by separate genes in plasmids inserted into bacteria. The protein chains are then chemically joined to form the final insulin product. Human growth hormone is also produced within bacteria, but special techniques are used because the bacteria do not usually produce human proteins. Therapeutic proteins produced by biotechnology include a clot-dissolving protein called tissue plasminogen activator (TPA) and interferon. This antiviral protein is produced within E. coli cells. Interferon is currently used against certain types of cancers and for certain skin conditions.
What is the mechanism by which gene therapy is used to treat certain forms of cancer?
Researchers and scientists are using gene therapy in two ways: to enhance the ability of healthy cells in fighting cancer, and to kill or prevent further growth for cancer cells. Replacing mutated genes with healthy genes, improving immune response, even introducing special genes that destroy cancer cells are examples of gene therapy that are treatments for cancer. An example would be a special form of cancer called melanoma, also known as skin cancer, is treated using gene therapy by injecting an anti-cancer protein called tumor necrosis factor that helps destroy cancer cells.
Source: http://www.cancer.gov/cancertopics/factsheet/Therapy/gene http://www.cliffsnotes.com/study_guide/Recombinant-DNA-and-Biotechnology.topicArticleId-8524,articleId-8439.html
How does deficiency in a certain protein contribute to ill health?
Protein is a necessary biomolecule used to synthesize amino acids needed by the body, in which it cannot manufacture alone. These amino acids help in repairing and maintaining many important parts of our body such as our organs and our bones. A deficiency of a certain protein would lead to the body taking protein from our muscles, therefore weakening them. Other symptoms of protein deficiency are weight loss, diarrhea and edema.
Source: http://www.wisegeek.com/what-is-protein-deficiency.htm
How is DNA technology adapted to the biochemistry of these proteins?
Recombinant DNA are DNA sequences that through molecular cloning, are able to create sequences not found in biological organisms. Through this technology, proteins may be synthesized in the laboratory, or DNA sequences replaced for gene therapy for treatments of several different diseases.
Source: http://en.wikipedia.org/wiki/Recombinant_DNA
What are the current AIDS treatments?
Vaccines represent another application of recombinant DNA technology. For instance, the hepatitis B vaccine now in use is composed of viral protein manufactured by yeast cells, which have been recombined with viral genes. The vaccine is safe because it contains no viral particles. Experimental vaccines against AIDS are being produced in the same way.
Diagnostic testing. Recombinant DNA and biotechnology have opened a new era of diagnostic testing and have made detecting many genetic diseases possible. The basic tool of DNA analyses is a fragment of DNA called the DNA probe. A DNA probe is a relatively small, single-stranded fragment of DNA that recognizes and binds to a complementary section of DNA in a complex mixture of DNA molecules. The probe mingles with the mixture of DNA and unites with the target DNA much like a left hand unites with the right. Once the probe unites with its target, it emits a signal such as radioactivity to indicate that a reaction has occurred. To work effectively, a sufficiently large amount of target DNA must be available. To increase the amount of available DNA, a process called the polymerase chain reaction (PCR) is used. In a highly automated machine, the target DNA is combined with enzymes, nucleotides, and a primer DNA. In geometric fashion, the enzymes synthesize copies of the target DNA, so that in a few hours billions of molecules of DNA exist where only a few were before. Using DNA probes and PCR, scientists are now able to detect the DNA associated with HIV (and AIDS), Lyme disease, and genetic diseases such as cystic fibrosis, muscular dystrophy, Huntington's disease, and fragile X syndrome.
Gene therapy. Gene therapy is a recombinant DNA process in which cells are taken from the patient, altered by adding genes, and replaced in the patient, where the genes provide the genetic codes for proteins the patient is lacking. In the early 1990s, gene therapy was used to correct a deficiency of the enzyme adenosine deaminase (ADA). Blood cells called lymphocytes were removed from the bone marrow of two children; then genes for ADA production were inserted into the cells using viruses as vectors. Finally, the cells were reinfused to the bodies of the two children. Once established in the bodies, the gene-altered cells began synthesizing the enzyme ADA and alleviated the deficiency. Gene therapy has also been performed with patients with melanoma (a virulent skin cancer). In this case, lymphocytes that normally attack tumors are isolated in the patients and treated with genes for an anticancer protein called tumor necrosis factor. The genealtered lymphocytes are then reinfused to the patients, where they produce the new protein which helps destroy cancer cells. Approximately 2000 single-gene defects are believed to exist, and patients with these defects may be candidates for gene therapy.
