Research and clinical trials double helix of DNA replication. Innovation continues his rapid progress as the basic research at universities and hospitals, funded partly by contributions from industry, research and the very pharmaceutical companies, makes new discoveries about the tissues and organs of living beings. Currently research in the laboratories of pharmaceutical companies focused their interest in finding improved treatments for cancer, central nervous system diseases, viral diseases such as acquired immunodeficiency syndrome (AIDS), arthritis and diseases the circulatory system, which are the ills afflicting mainly the developed countries, and ultimately, they generate more profits.Little research is done on prevalent diseases in developing countries (for example, Chagas disease in South America), because the return on investment in these markets is low. The discovery of the structure of deoxyribonucleic acid (DNA) at the beginning of the 1950s made possible the development of new techniques that have resulted in the production of prostaglandins, interferon, new vaccines, blood clotting factor and many other complex biochemical compounds that previously were difficult or impossible to machine. The directors of pharmaceutical companies fully understand the importance of genetic engineering to develop new drugs today and tomorrow. The use of live animals in medical research is the subject of controversy. Although pharmacologists have developed and continue to develop techniques to avoid its use, live animals (mainly rats and mice) remain crucial for many procedures.Medical supervision agencies insist that you have to use two different species to verify their possible toxicity of a new substance before granting permission to begin clinical trials. The first phase of these trials involves the voluntary cooperation of healthy people are given a brief treatment of the new drug. If problems arise, the official body that granted the authorization allows the start of the second phase of trials in which a few specialist advisers try the product with a selected group of patients. Based on their recommendations, the company can request permission to conduct the third phase of testing, of a broader nature. If this last step yields satisfactory results, is seeking approval of the drug. In some cases it is necessary to repeat a similar procedure in countries where it wants to market. Usually tests are carried out in hospitals, where you can organize so-called double-blind trials.Patients were divided into two or three groups, one of them receiving the drug to be proved, the other receives a placebo (an inactive substance) and sometimes a third group received another product that you want to compare the new drug. All three compounds are presented in a way that neither the patient nor the physician can differentiate them. According to some designs, only the hospital pharmacist know which group receives each compound and does not disclose the results until the end of the trial, when doctors have evaluated clinical outcomes. In the case of medicines for animals, similar trials are conducted that are performed by veterinarians. Today most Western governments believe that a requirement for production and distribution of safe and effective drugs that the pharmaceutical industry is to continue in the hands of private enterprise.Another requirement is the establishment of governmental monitoring bodies composed of experts and empowered to grant or refuse licenses to pharmaceutical companies to market their products according to criteria of their quality and patient safety. These monitoring bodies are responsible for preventing abuse or irresponsibility on the part of manufacturers, thereby reducing the chance to appear and health hazards arising from disasters like thalidomide.