Tracing the roots of the idea of dialysis: a leap of 20 centuries--from "catharsis" to dialysis.

In this article, we comment on a primitive foresight of Galen's regarding the value of blood purification. His main arguments are based on: (i) The disease-blood concept, i.e., the idea that blood can be unclean (with an either excess or bad-quality humor) and thus cause a disease; (ii) Cure can be achieved if elimination (catharsis in Greek) of the humor (toxin) is possible; (iii) If the toxins are limited in the intravascular space, their elimination will be sufficient for cure by just a single attempt of replacing the unclean blood with pure; (iv) If the toxins have also affected the extravascular space, then repeated attempts will be needed; (v) The whole procedure can be compared with the insufficiency of washing once a dirty clay pot and immediately filling it with a pure liquid. The dirt that has adhered to the pot's walls will contaminate the pure liquid. Thus, repeated washing is needed to achieve cleanliness. Galen's metaphor of washing a dirty pot for a long period and eventually achieving a pure content is strikingly similar to the theory of hemodialysis. According to this, uremic toxins are spread both intravascularly and extravascularly. To eliminate them, long and repeated "washing" of the blood is needed. One of the reasons the first attempts to dialyze failed was that this "washing" procedure was inadequate (the other reasons were clotting of the blood, infections and access problems).

On some exotic urine colors in ancient and Byzantine Greek literature.

This work does not analyze the entire subject of uroscopy but focuses on a very small part thereof: i.e., some rare urine colors, in particular green and blue. These are so rare that most modern nephrologists have never encountered them. We conducted a small survey comparing contemporary knowledge with that of the past, with the participation of 40 Greek nephrologists (25 juniors and 15 seniors). Of these, 63% rejected the notion that green or blue urine even exists, while of those who were aware of them, only 20% had personally encountered them. According to our search of the modern literature, such colors result from either consumption of green or blue pigments, liver dysfunction or urine infection by certain bacteria. We searched and traced several passages on these rare urine colors, referred to in ancient Greek fewer than 7 different names, in the Greek medical literature of the Classical, Roman and Byzantine eras. In these passages, the authors not only gave detailed descriptions of the medical conditions of the corresponding patients but also explained this appearance of the urine. Surprisingly, in the studied texts we also found identical explanations with those in modern texts: consumption of certain foods, liver disease and inflammation. We present and comment on these passages, concluding that many uroscopical findings of antiquity were not quackery, but rather reliable medical statements based on thorough observation and rational reasoning.

The late Greco-Roman and Byzantine contribution towards the evolution of laboratory examinations of bodily excrement. Part 2: sputum, vomit, blood, sweat, autopsies.

Although the establishment of medical laboratory institutions was a continuous process that matured only after the 16th century, several attempts had already been made to attain a diagnosis by investigating bodily excrement. In the first part of our work, published in a previous issue of this journal, we presented data on urine, sperm, menses and stools. In this paper we present data on sputum, vomit, blood, sweat, and autopsies, thus completing the list of human materials used for laboratory examinations. All the data used are extracted from codices of Late Antiquity and Byzantium and translated by us. We did not study medical texts from the other great ancestors of Western medicine, namely Arabic and Jewish writings. From the texts cited, it is apparent that the lack of technological means was no obstacle for the doctor to create an "examinational" mind, i.e., to try to correlate the macroscopic findings in the excrement with the pathophysiological mechanism that induced them, solely with the use of the senses. This not only applies to the examination of urine, as is commonly assumed, but also to many other excrements of the upper and lower orifices of the body, as well as the human body as a whole.

The late Greco-Roman and Byzantine contribution to the evolution of laboratory examinations of bodily excrement. Part 1: Urine, sperm, menses and stools.

It is a common belief that laboratory investigation processes were developed after the 16th century and that before that time no attempts were made to attain a diagnosis by investigating material coming from the human body. In this paper we present data extracted from Byzantine codices that support the following thesis: The idea of examining human excrement for diagnostic purposes has its roots in the Roman and Byzantine eras. The lack of technological means was no obstacle for the doctor to create an "examinational" mind, i.e., to try to correlate the macroscopic findings in the excrement with the pathophysiological mechanism that induced it, using only the human senses.