Whither Clinical Pathology?: Trends and Opportunities.

At the turn of the half-century, a little over a year ago, I was asked to contribute an article to the British Medical Journal on " Fifty Years of Clinical Pathology " as one in a series of articles on the same theme in other branches of medicine. The composition of that article was intensely interesting and highly self-educative. The study of the historical facts revealed certain milestones which themselves had given rise to trends in the subject which is our own. I have thought, therefore, that it might be of interest to try to think out what are likely to be the trends of clinical pathology in the years ahead, atomic bombs permitting, bearing in mind, first, the speed and trends of scientific advance, secondly, the impact of nationalization upon the practice of medicine, and, thirdly, what we can do to prevent the personal side of our particular craft from being submerged in the impersonality of the State. Let us, in the first place, consider the speed of scientific advance in relation to what may be called the growing points of medicine. None can doubt that chemistry has come to be the foundation of nearly all scientific procedures, for it forms the fundamental basis of many of the laboratory manceuvres which hitherto, or until recently, we have performed by rule of thumb. A few examples will make this concept abundantly clear. For many decades we have used this or that medium for the cultivation of particular bacteria. These media were devised on an empirical basis-by trial and error, indeed, on much the same principles as governed therapeutics until relatively recent times. Now we appreciate that a particular medium will grow a particular organism because of the metabolic requirements of that organism, to wit, on account of the chemistry of its vital processes. Our empirical media contain this or that specific substance which is essential for the organism. Likewise with histological staining. Whereas at one time a process of trial and error determined the best stain for a particu!ar tissue and stains which provided the best specific contrast for this or that material, we now know that the virtues of these different stains depend upon their affinity for particular chemical groupings in the tissue itself. Cytochemistry or histochemistry is now a science of its own, and the application of a stain has as its object the demonstration of a specific chemical substance, rather than the production of a pleasant contrast histological picture.