INTRODUCTION 



I 



n terms of the bodv, injury may be denned as a harmful event 

 or an unfavourable environmental development, intrinsic or ex- 

 trinsic. Pathology is the study of such injury and of the body's re- 

 action to it, and injury and reaction to injury combine inextricably 

 to produce the state we recognise as disease. 



Pathology was first studied in a purely structural frame of 

 reference first in organs, then in tissues, finally in the cell. Hard 

 on the heels of morbid anatomy came the recognition of disordered 

 function, to be followed by the exploration of abnormal cell chemis- 

 try. 



It is this latter phase of the study of disease with which this small 

 book is concerned and it will be quickly apparent to the reader 

 that the chemistry of cell injury is still in the infantile stage of 

 development. Indeed, there are great sectors in which virtually 

 nothing is known and we have not deemed it desirable to attempt 

 to conceal these deficiencies. On the other hand where sufficient 

 reliable evidence has been accumulated to justify formulation of 

 an explanatory hypothesis this has been presented, albeit with the 

 reservation that further evidence may destroy what others have 

 devised. 



Finally, certain topics have been omitted as an act of policy. 

 Examples of this exclusion are carcinogenesis and virus-host inter- 

 relationships. These aspects of cell injury constitute major subjects 

 in themselves and have been amply discussed elsewhere by special- 

 ists. Even in the spheres which have been discussed it will be 

 apparent that there has been no attempt at complete coverage, but 

 rather an effort to use examples of natural and experimental disease 

 as illustrations of a general theme. 



The authors would like to express their indebtedness to their 

 colleagues, Drs. M. J. R. Dawkins and K. R. Rees for much invalu- 



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