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Even though the extraordinary advances made in medicine during the last century have extended the average human life span from about 30 years at the dawning of the Twentieth Century to 76 at the beginning of the new millennium, man continues to consider eternal youth as a much longed-for utopia. Lifespan is still limited by the impossibility of finding new organs to replace those damaged by age, accidents or disease and by the lack of cure for cancer and infectious and cardiovascular diseases. However, scientific advances during the 1990´s began to plant the idea that, even if eternal youth is not yet within our grasp, extending the lifespan up to 150 years will be a possibility within the next quarter-century.
Gene therapy is the administration of genes to a patient for therapeutic purposes. It intends to restore a function that has been lost because of a defective gene by giving the patient a functional one. As you can see, it is a very simple concept--to replace a faulty gene for a healthy one. However, there are three practical problems: The isolation of the gene in question, the insertion of the gene in the right place in the genome and an appropriate vehicle to deliver the gene. The first problem has been solved in all of the trials that have been carried out up to now. That is, the genes to be administered have been isolated and characterized. And with the Human Genome Project coming to an end in the very near future, there is no doubt that many more genes related to or associated with diseases will be isolated. Thus, this part of GT presents no problem at the moment. The second problem has not been solved yet and there are few reports indicating what sort of advances are being made in this area. If you read my first article, you already know that for a gene to function properly it must be: a. expressed at the right time, in the right tissue and in the precise amounts, and, b. located in the right chromosome and under its normal regulatory sequences. Thus, if it is going to be done correctly, gene therapy should directly replace the defective gene with the healthy one. The way to solve this problem is to use a delivery vehicle or vector that inserts the gene into the right chromosomal location. At this time, there are no vectors capable of doing this.
The copyright of the article MOLECULAR AND CELULLAR MEDICINE ADVANCES = ETERNAL YOUTH? Part I in Molecular Biology/Medicine is owned by . Permission to republish MOLECULAR AND CELULLAR MEDICINE ADVANCES = ETERNAL YOUTH? Part I in print or online must be granted by the author in writing.
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