HISTORY OF MEDICINE- WEST

Ancient Greek medicine can be divided into 5 stages: Homeric, Mythological, Pre-Hippocratic, Hippocratic, and Post Hippocratic

HOMERIC MEDICINE: 9th century BC; description based on oral tradition, archeology, writings.

MYTHOLOGICAL:

PREHIPPOCRATIC : 6th century BC

SUMMARY OF MEDICAL PRACTICE AT TIME OF HIPPOCRATES:

No longer believed illness caused by Gods, but little effective treatment available. If patient couldn't be improved or cured, abandoned by practitioners. Patient in better state since now would be the subject of rational treatment.

THEORY

TRAINING

METHODS

HIPPOCRATES - 460 BC - 370 BC (approx.)

Had most profound influence on Western and some aspects of Eastern medicine of anyone in history. His esteem increased with time, as his legend (based on truth or rumor) grew. A collection of his works, "Corpus Hippocraticum" (72 books), probably including contributions from others, was assembled in 4th cent. BC in library, established by Ptolmey, at Alexandria, Egypt. First to mention 4 humors. Balance of 4 humors determines the state of the microcosm (body) as the state of the world (macrocosm) was determined by the 4 elements (which were formalized by Aristotle). Ideas in his books:

Hippocratic Oath

Hipppocratic Method

Rational methods free of religious or supernatural thinking were great advance in medical practice.

POST HIPPOCRATIC - splits into variety of sects.

Plato - (see History of Science - West)

Aristotle (see History of Science - West);

4 Humors in Greater Detail (from The Greatest Benefit to Mankind - Ray Porter)

Phlegm and bile were associated with disease, since they became evidence in sickness.  Cold in winter were associated with excess phlegm, while summer diahrrea and vomiting were associated with bile.  Of the 60 books in the Hippocratic Corpus, one, Airs, Waters, and Places details information on disturbance in the humors.  Since blood was released during menstruation, it was likely that blood letting would also have therapeutic effects.  Black bile was seen in feces and vomit.   The four humors could be correlated through analogy to the four qualities, four seasons, four ages of people (infancy, youth, adulthood, and old age) and four temperments (melancholyi, choleric, sanguine and phlematic).  For example

SUMMARY OF MEDICAL PRACTICE IN ROMAN EMPIRE:

Greek medicine reached peak in Alexandria, and then moved to Rome which controlled much of the area. Early Roman medicine based on Gods, but eventually gave way to more rational approaches. Greek culture become predominant part of intellectual life in Rome. Many Greek physicians came to Rome.

Asclepiades (around 100 BC) -

GALEN - 129-200 (approx.)

Greek physician and most influential writer of all time on medicine. This work was basis for medicine for 1500 years. Careful and accurate, but uncritical observations. Worked in Alexandria and Rome. Wrote huge amount about anatomy, physiology, pharmacology, pathology, therapy, dietetics, hygiene, philosophy, all in Greek, the language of science. Scholars accepted his work blindly. Considered first experimentalists.

CHARACTERISTICS OF WRITING

To describe the body, Greeks and Romans used metaphors derived form domestic scenes and agriculture. Galen thought the slow flow of blood to nourish the limbs and organs was like a great irrigation system. He thought the blood didn't circulate. Originates in liver, goes through veins. Blood in arteries flows from heart, and when reaches brain produces animal spirit. Only contact between the two flows were through pores in heart. Lungs bring air to heart, and discharge smoky vapors produced when air reached the invisible fire in the heart (like a hearth).

USE OF MEDICATION

CONCEPT OF BLOOD

WHY DID HIS WORK LAST SO LONG?

GRAPHIC:  PHYSIOLOGY OF GALEN

MEDICINE AND THE RISE OF CHRISTIANITY

MEDICINE AND THE DARK AGES

MEDICINE AND THE RISE OF ISLAM (Muhammad 570-632)

First five centuries of Christian era, much of Greek scholarship lost. However, in the 7th century, the new religion of Islam started to preserve remains of ancient scholarship and bring it back into Europe. Arabs had great respect for learning, and became the vessel for ancient Greek/Roman learning. They translated and extended the ancient knowledge, especially in philosophy, math and science.

Equal to Galen in both Islam and Christian world. Boy prodigy. Principle contribution as compiler and commentator. Wrote 100 books, most famous The Canon, which was basis for much medicine, even until mid 17th centuries in Christian Universities. Tried to reconcile Galen with Aristotle.

MEDICINE AND THE RISE OF UNIVERSITIES

Real medical education established in new universities such as Salerno, Monpellier, and Paris:.

MEDICINE AND THE MIDDLE AGES

Western Europe emerged from dark ages about 1000 AD, but still another 500 years before middle ages ended. French culture with combination of faith, feudalism, and chivalry model for Europe. Each person had role/function. Mediterranean culture in disarray.

MEDICINE AND THE RENAISSANCE

Many factors drove the changes that became the Renaissance: a desire to return to cultural ideas of ancient Romans and Greeks, the invention of the printing press which decrease the cost of books which also became available in the vernacular, the development of trade resulting from the Crusades and the development of local industry, leading to a money economy, and the discovery of sea routes to India and America. After Turks capture Constantinople in 1453, a large influx of Greek scholars into northern Italy occurred. The Universities there (Bologna, Padua, etc.) attracted scholars from all Europe. The best publishing houses developed in Florence and Venice. Northern Italy was also the western end of the Silk Road, from which goods were transported to and from China. The arriving Greek scholars de-emphasized Aristotle, Galen, and Scholasticism, while supporting Hippocrates and open observation. With the 17th century and the Age of Scientific Revolutions, major intellectual shifts occurred. People shifted to asking how things happen rather than why they occur? Speculation was replaced with experiment, and interpretations became mechanical. Three forces had to be dealt with:

PARACELUS: 1493-1541

VESALIUS - 1514-1564

HARVEY: 1578-1657

DESCARTE - 1637

BASIS OF MODERN MEDICINE

Germ Theory of Disease - Infectious Disease

The Emergence of Modern Medicine in America in the 19th Century:

Post-Genomic Medicine

Guides to Use of Medical Literature

In analyzing the results of a published medical study, you must have confidence that the results of the study are valid - i.e. that they conclusions follow directly from the observations - and that you understand the results of a treatment.   Consider an article published in the Journal of the American Medical Society (1993) 270, pg 2598-2601 entitled, "How to Use an Article About Therapy and Prevention" and "How to Use an Article About Harm", JAMA (1994) 271, pg 1615-1619.

Are the results of the study valid?:     Do the results represent an unbiased estimate of a treatment's positive effects or of a potential toxic effect of exposure or have they been influenced in some systematic fashion to lead to a false conclusion?  Several factors must be considered?

A.  Where there clearly identified comparison groups (experimental vs. control) that were similar with respect to important determinants of Outcomes other than the one of interest - i.e. the dependent variable?   Three kinds of trials have been used in such assessments:

  1. Randomized Control Trials (RCT) - An experiment in which patients are assigned in a random fashion to the experimental group (i.e.   given a treatment of unknown efficacy) or control groups (i.e. for a treatment study, given a placebo or standard therapy).  RCT are rarely used for harm studies.   The power of RCT stems from the fact that patients are randomly selected which raises the probability that experimental and control groups are identical except for the experimental treatment. 
  2. Cohort Studies - Used when it is impossible or unethical to perform a RCT.  In this study the investigators identifies two groups of people:  one using a particular treatment or exposed to a potentially harmful agent and another not using the treatment or not exposed.  The participants are followed to determine difference in effects of treatment or exposure to harm with time.  An example would be to select men (or women)  exposed to toxins in a given industry and assess the health status of their children.  Alternatively, cohort studies can be done when the outcome is infrequent.  Since the people in the study are not randomly picked (since they pick themselves or are picked by doctors), members of the exposed group may be different in other characteristics  from the control.  Investigators must show that the groups are similar (except with respect to the dependent variable) or use statistics to adjust for any differences.  (For example, a study for GI bleeding in people who take non-steroidal anti-inflammatory drugs (NSAID) should be controlled for age, since increased age as well as increased use of NSAID are associated with GI bleeding.)  Even then other confounding variables might be associated with the effect, such as if illness for which people use NSAID might cause GI bleeding
  3. Case Control - Used if outcome very rare or takes long to develop.  Investigators select people  with specific outcome and then chooses controls without that outcome but as similar in other ways to experiment group (ex:  identical in age, sex, weight, etc). then ascertain past exposure to therapy or toxins in both groups.  (For example, show association between DES intake by pregnant women and development of cancer in their daughters. 
  4. Case Reports - Do not use control groups and are merely descriptive.   

B.  Were the exposures to potentially toxic agent and the outcomes (of RCT and cohort studies)  measured the same in both experimental and control groups?  For example, in a case control study, when asked about prior exposure to solvents, patients in the experimental group (with leukemia) might be more likely to recall and report previous exposure because of greater motivation (recall bias) or greater probing by an interviewer (interviewer bias).   Exposures to potentially toxic agents should also be for a similar length.   In a cohort study, a three-fold increase risk of cancer in radiation workers might be explained by a physician who was aware of the risk doing a more thorough assessment of the patient which might detect disease earlier or disease that would ordinarily go undetected (surveillance bias). 

C. Were the patients available for follow-up for a sufficiently long enough period of time?  If patients are not available for follow-up, the validity of the study might be compromised since that that remain available might have different prognosis than those who aren't available. 

D. Were patients analyzed in the groups to which they were randomized?  If someone in a experimental group taking a drug become noncompliant and don't take the medication, they should not be excluded from the analyses.   Often these patients fared worse.  Excluding them (while leaving similar patients in the control group) leaves behind those who might have gotten better, and removes the unbiased nature of the RCT. 

E.  Were patients, clinicians, and study personnel "blind" to treatment?  If a patient knows they are on a new therapy, they will have an opinion about its efficacy, as will the practitioner and others involved in the study.  The opinions can systematically distort aspects of the treatment, reporting of outcomes, and introduce bias of the medical personal into the assessment of the treatment efficacy.  Best way to avoid is performing a double-blind study (for drug studies, using a placebo  for the control group and target drug for the experimental group).

BIBLIOGRAPHY

The information for the time line and descriptions come directly and often verbatim from a variety of sources, including:

Butterfield, H. The Origins of Modern Science. Free Press, 1965

Lyons, A. and Petrucelli, R. Medicine: An Illustrated History. Abradale Press, 1987.