Wednesday, December 2, 2009

Medicene History

Prehistoric medicine incorporated plants (herbalism), animal parts and minerals. In many cases these materials were used ritually as magical substances by priests, shamans, or medicine men. Well-known spiritual systems include animism (the notion of inanimate objects having spirits), spiritualism (an appeal to gods or communion with ancestor spirits); shamanism (the vesting of an individual with mystic powers); and divination (magically obtaining the truth). The field of medical anthropology studies the various prehistoric medical systems and their interaction with society.

Early records on medicine have been discovered from early Ayurvedic medicine in the Indian subcontinent, ancient Egyptian medicine, traditional Chinese medicine and ancient Greek medicine. Earliest records of dedicated hospitals come from Mihintale in Sri Lanka where evidence of dedicated medicinal treatment facilities for patients are found.Early Greek doctor Hippocrates, who is called the Father of Medicine, and Galen laid a foundation for later developments in a rational approach to medicine. After the fall of the Western Roman Empire and the onset of the Dark Ages, the Greek tradition of medicine went into decline in Western Europe, although it continued uninterrupted in the Easern Roman Empire (Byzantium). After 750, the Muslim Arab world had Hippocrates' and Galen's works translated into Arabic, and Islamic physicians engaged in some significant medical research. Notable Islamic medical pioneers include polymath Avicenna, who, along with Hippocrates, has also been called the Father of Medicine, Abulcasis, the father of surgery,Avenzoar, the father of experimental surgery, Ibn al-Nafis, the father of circulatory physiology, andAverroes.Rhazes, who is called the father of pediatrics, was one of first to question the Greek theory of humorism, which nevertheless remained influential in both medieval Western and medieval Islamic medicine During the Crusades, one Muslim observer famously expressed a dim view of contemporary Western medicine.However, overall mortality and mordibity levels in the medieval Middle East and medieval Europe did not significantly differ one from the other, which indicates that there was no major medical "breakthrough" to modern medicine in either region in this period. The fourteenth and fifteenth century Black Death was just as devastating to the Middle East as to Europe, and it has even been argued that Western Europe was generally more effective in recovering from the pandemic than the Middle East. In the early modern period, important early figures in medicine and anatomy emerged in Europe, including Gabriele Falloppio and William Harvey.

An ancient Greek patient gets medical treatment: this aryballos(circa 480-470 BCE, now in Paris'sLouvre Museum, probably contained healing oil

The major shift in medical thinking was the gradual rejection, especially during the Black Death in the 14th and 15th centuries, of what may be called the 'traditional authority' approach to science and medicine. This was the notion that because some prominent person in the past said something must be so, then that was the way it was, and anything one observed to the contrary was an anomaly (which was paralleled by a similar shift in European society in general - see Copernicus's rejection of Ptolemy's theories on astronomy). Physicians like Ibn al-Nafis and Vesalius improved upon or indeed rejected the theories of great authorities from the past (such as Hippocrates, and Galen), many of whose theories were in time discredited.

Modern scientific biomedical research (where results are testable and reproducible) began to replace early Western traditions based on herbalism, the Greek "four humours" and other such pre-modern notions. The modern era really began with Robert Koch's discoveries around 1880 of the transmission of disease by bacteria, and then the discovery of antibiotics around 1900. The post-18th century modernity period brought more groundbreaking researchers from Europe. From Germany and Austrian doctors such as Rudolf Virchow, Wilhelm Conrad Röntgen, Karl Landsteiner, and Otto Loewi) made contributions. In the United Kingdom Alexander Fleming, Joseph Lister, Francis Crick, and Florence Nightingale are considered important. From New Zealand and Australia came Maurice Wilkins, Howard Florey, and Frank Macfarlane Burnet). In the United StatesWilliam Williams Keen, Harvey Cushing, William Coley, James D. Watson, Italy (Salvador Luria),Switzerland (Alexandre Yersin), Japan (Kitasato Shibasaburo), and France (Jean-Martin Charcot, Claude Bernard, Paul Broca and others did significant work. Russian (Nikolai Korotkov also did significant work, as did Sir William Osler and Harvey Cushing.

As science and technology developed, medicine became more reliant upon medications. Throughout history and in Europe right until the late 18th century not only animal and plant products were used as medicine, but also human body parts and fluids.Pharmacology developed from herbalism and many drugs are still derived from plants (atropine, ephedrine, warfarin, aspirin, digoxin, vinca alkaloids, taxol, hyoscine, etc). The first of these was arsphenamine / Salvarsan discovered by Paul Ehrlich in 1908 after he observed that bacteria took up toxic dyes that human cells did not. Vaccines were discovered by Edward Jenner and Louis Pasteur. The first major class of antibiotics was the sulfa drugs, derived by French chemists originally from azo dyes. This has become increasingly sophisticated; modern biotechnology allows drugs targeted towards specific physiological processes to be developed, sometimes designed for compatibility with the body to reduce side-effects. Genomics and knowledge of human genetics is having some influence on medicine, as the causative genes of most monogenicgenetic disorders have now been identified, and the development of techniques in molecular biology and genetics are influencing medical technology, practice and decision-making.

Evidence-based medicine is a contemporary movement to establish the most effective algorithms of practice (ways of doing things) through the use of systematic reviews and meta-analysis. The movement is facilitated by the modern global information science, which allows all evidence to be collected and analyzed according to standard protocols which are then disseminated to health care providers. One problem with this 'best practice' approach is that it could be seen to stifle novel approaches to treatment. The Cochrane Collaboration leads this movement. A 2001 review of 160 Cochrane systematic reviews revealed that, according to two readers, 21.3% of the reviews concluded insufficient evidence, 20% concluded evidence of no effect, and 22.5% concluded positive effect.