Chapter-1 Medicine in 21st Century— Where Are We Heading?

“The new millennium is a remarkable time for medicine, when the potential for bettering human health is unequalled in history. Despite the potential obstacles and unforeseen challenges, the possibilities for progress in medical science and the opportunities for medical research have never been greater. The ongoing revolution in biomedical science is of an unprecedented magnitude, is accelerating dramatically, and promises almost unlimited opportunity for the betterment of humankind. ” (David Nathan, pediatric hematologist writing in a special issue of JAMA 2001).1 SEQUENCING OF THE HUMAN GENOME In 1944 Avery, McCloud, and McCarty showed that DNA is the stuff that genes are made of and in 1953 the double helical, anti-parallel, complementary nature of DNA was published by James Watson and Francis Crick and finally, in 2003, we marked the completion of the “finished sequence ” of the human genome.2-5 The chemical consequences of the complementary structure of DNA underlie much that we do today in molecular biology and genomics. This knowledge of basic science has been accompanied by a phenomenal burst of technology with the ability to amplify DNA using the polymerase chain reaction [PCR], rapid identification of sequenc