Comparative medicine

Comparative medicine is a distinct discipline of experimental medicine that uses animal models of human and animal disease in translational and biomedical research.:2 In other words it relates and leverages biological similarities and differences among species to better understand the mechanism of human and animal disease. It has also been defined as a study of similarities and differences between human and veterinary medicine including the critical role veterinarians, animal resource centers, and Institutional Animal Care and Use Committees play in facilitating and ensuring humane and reproducible lab animal care and use. The discipline has been instrumental in many of humanity's most important medical advances. Comparative medicine is a distinct discipline of experimental medicine that uses animal models of human and animal disease in translational and biomedical research.:2 In other words it relates and leverages biological similarities and differences among species to better understand the mechanism of human and animal disease. It has also been defined as a study of similarities and differences between human and veterinary medicine including the critical role veterinarians, animal resource centers, and Institutional Animal Care and Use Committees play in facilitating and ensuring humane and reproducible lab animal care and use. The discipline has been instrumental in many of humanity's most important medical advances. The first documented mention of comparative pathology comes from Hippocrates (460 - 370 BCE) in Airs, Waters, Places where he describes relevant case histories for horse herds and human populations. He insists that diagnosis be based on experience, observation, and logic. Aristotle (384 - 322 BCE) hypothesized about interspecies transmission of disease.:4 The anatomy and physiology schools opened in Alexandria by Erasistratus (404 - 320 BCE) and Herophilus (330 - 255 BCE) were directly inspired by Aristotle's work. Although most of the documents were destroyed when the Library of Alexandria burned. In his Disciplinarum Libri IX, Marcus Terentius Varro (c. 100 BCE) made early indications of the germ theory of disease with his conception that tiny invisible animals carried with the air caused disease by entering through the nose and mouth. He also warned people against establishing homes near swamplands. Aulus Cornelius Celsus (25 BCE - 50 CE) wrote of experimental physiology in De Medicini Libri Octo detailing numerous dissections and vivisections he performed and pointed out specific interventions as well, such as cupping to remove the poison of a dog's bite.:8 By the time of Claudius Galen (129 - 200 CE), whose name lives on in the term Galenic formulation, human dissection was no longer acceptable and his vivisection studies of comparative anatomy relied mostly on the use of Barbary macaques. This resulted in several persistent misunderstandings of human anatomy. Another key early contributor to early comparative medicine through publication of his Digestorum Artis Mulomedicinae libri in 500 CE was Publius Flavius Vegetius Renatus. A work that continued to be published and used in medicine as late as the 16th century.:5 The post-antique European world gave rise to a dominant monotheistic culture and with it a de facto ban on human dissection. As such, there was a slow down in comparative medicine's progress through the middle ages. This was to be codified in 1637 CE with René Descartes manuscript Discourse on the Method.:11 The Persian physician Muhammad ibn Zakariya al-Razi (865 - 925 CE) was the first to describe smallpox and measles and prescribe treatments, making his discoveries largely through animal dissection. Due to the far flung nature of their travels the Crusaders imported the Oriental rat flea carrying the bacterium Yersinia pestis and eventually initiating the Black Death. The massive deleterious effect of the pandemic brought on serious consideration of inoculation and transmission chiefly through the work of Albertus Magnus (1206 - 1280 CE). In the book Liber de Animalibus he discussed human and animal plagues in addition to narrowing down the method of transmission to bites, contact with animals, or respiration of sick air from the diseased. Girolamo Fracastoro (1478 - 1553 CE) outlined a concept for rapidly multiplying minute bodies (germs) transmitting infection in De contagione et contagiosis morbis. The theory was widely praised but fell into disuse until Louis Pasteur and Robert Koch developed an empirical version. The beginnings of microbiology, and thus serious use of comparative medicine, were finally enabled by Antonie Philips van Leeuwenhoek's refinement of the microscope and subsequent observation of animalcules. The first real basis for the structured and regular exchange of knowledge of science and medicine in the western world was established with the 1660 founding of the Royal Society in London. Robert Doyle (1627 - 1691) published key experiments in their classical journal Philosophical Transactions among them interspecies blood transfusion, including from sheep into men. The 18th century brought new plagues and faster communications to Europe creating a fruitful environment for a comparative approach to transfer and contagion. Along with the technology of transference as an experimental in vivo approach to medicine.:7 At this stage it was already established in China that it was possible to use pox crusts as an effective treatment for smallpox infections. Emanuel Timone (1665 - 1741) was the first westerner to publish anything on inoculation, which he called grafting, although it's unclear if he developed it de novo (as new) or inferred it from previous work.