To understand molecular biology

Objectives: To display theorical and methodological basis of the molecular biology. To point out its main medical applications. Data sources: For this review, we analysed the English and French literatur e concerning the research and clinical aspects of the molecular biology, es pecially in anaesthesiology and intensive care, using the Medline(R) databa se. The current textbooks were also used. Study selection: We selected: 1) the original articles corresponding to the main advances that resulted in the present state of this discipline; 2) th e reviews; 3) some chapters of textbooks. Data extraction: In this review, we report: 1) the current knowledge concer ning the conservation and the expression of the genome; 2) the principles o f the most widely used experimental techniques; 3) the medical applications of this knowledge in anaesthesiology and intensive care; 4) the more recen t developments of this research field. Data synthesis: Within medical biology, molecular biology essentially corre sponds to the study of nucleic acids. In this review, the general principle s governing the organization and expression of the genome are discussed. Th e expansion of molecular biology has been a consequence of the widespread u se of enzymatic tools, of which bacterial restriction enzymes were the firs t. Numerous enzymes are now available, permitting DNA strands to be cut, li nked, synthesized and sequenced. Several of the most representative molecul ar biology techniques are described. Some of them, such as PCR, are commonl y used in clinical situations. Animal experimental models have also been ge nerated by genome altering methods, in order to analyse the phenotypic cons equences of these modifications. Recently, a viable mammal, deriving from a differenciated cell, has been cloned. Human embryonic totipotent stem cell s are now available in cultures. These advances have important ethical impl ications whilst, at the same time, offering new opportunities far medical a pplications. The state of gene therapy and human genome sequencing programm es is discussed. (C) 1999 Elsevier, Paris.