'Ur-ine the know'

The clinical investigation team comprised of our Nephrology/Urology Centerat the University of Minnesota, meets daily to discuss progress that hasbeen made, problems that need solutions and plans for the day.

Before we end our discussion, we take turns sharing "words of wisdom."

One of our favorite topics falls under the theme called "ur-inethe know," phonetically translated as "you're in the know."

To the readers of this month's Diagnote, I say, "ur-ine" storefor some fascinating knowledge about the mark urine has made on the worldof medicine.

Did you know that?

References to the art of diagnosing diseases of animals and man fromthe examination of urine can be traced back for thousands of years to thefirst written records of civilization.

Babylonian and Egyptian physicians began the art of uroscopy, which eventuallydeveloped into extensive and sometimes ritualistic examination of the appearanceof urine collected in special bladder-shaped flasks (called urinals or urineglasses).

In those days, the physicians often did not see the patients, but onlytheir urine. They lacked the sophisticated methods of testing urine commonlyused in our era, but they were able to obtain diagnostic clues from basicobservations of the physical characteristics of urine including, volume,color, turbidity, odor, sediment and even sweetness.

Although contemporary urinalysis also includes chemical analysis andmicroscopic examination of urine sediment, these same physical characteristicsof urine are included in our diagnostic evaluation of patients today.

The Hindus of ancient times identified the disease diabetes mellitusby the name "honey urine," because they observed that black antswere attracted to sweet urine. These insects were used as a means of diagnosisof diabetes mellitus, and this is one of the oldest diagnostic tests knownin the history of science.

This observation lay dormant for centuries until Thomas Willis in 1664rediscovered the sweet taste of urine produced in association with diabetesmellitus, and thus was able to distinguish this disease from other conditions.

The Greek words "mellitus" (meaning honey and implying a sweettaste) and "insipidus" ("in" is a prefix meaning withoutand "sapid" means "taste") were then used to describedifferent types of diabetes.

Diabetes, a term derived from Greek and literally meaning "to passthrough," was used to refer to conditions associated with formationof large volumes of urine. Diabetes mellitus meant that abnormal quantitiesof sugar were passing through the urinary tract, while diabetes insipidusmeant abnormal quantities of tasteless (non-glucosuric) urine were beingformed.

In past times, the old French term "pissier" was often usedto describe urine. From this term "pissier" comes the Englishterm "piss," in use as a noun and a verb before the time of theEnglish Bible translator Wycliff (1324-1384). According to Webster's Unabridgeddictionary, ants were named "pismire" because they dischargedan irritant fluid thought to be urine. Wycliff used the word pismire intranslating the word "ant" at Proverbs 6:6. However, the word"piss" has not been considered polite in the English languagesince the spread of Puritanism.

Uroscopy

As mentioned, Hippocrates (400 B.C.), the Greek father of medicine, frequentlywrote about the importance of uroscopy. By the 16th century, charts hadbeen developed describing the significance of up to 20 different colorsof urine.

However, the credibility of the urinalysis became compromised when charlatanswithout medical training began offering their predictions based on uroscopyto the public for a substantial fee. Many of these quacks, called "pisseprophets" and "water doctors," did not hesitate to extendtheir predictions (called urine casting and water casting) beyond the rangeof medicine. In their hands, uroscopy became uromancy (the Greek suffix"mancy," refers to divination), lost scientific value and threwdiscredit on the observations of ethical workers in this field of study.These quacks, who often wore elaborate gowns and headdress, became the subjectof a book published by Thomas Bryant in 1627.

This expose helped to inspire the first medical licensure law proposedby Thomas Linacre, founder of the College of Physicians in England, anotherexample of how urine left its mark on the practice of medicine.

Until the 17th century, the diagnosis of disease from urine had alwaysbeen based on appearance alone. The quantitative study of urine began in1655 when Jan Baptista Van Helmont accurately determined the specific gravityof urine by weighing it in a glass vessel with a narrow neck and known tohold a certain volume of rainwater.

He then noted the dilute nature of urine excreted after ingestion ofwater and the concentrated nature of urine excreted after abstention fromdrinking and associated with fever. These observations provided the insightthat led to recognition of diagnostic errors frequently associated withexamination of randomly collected urine samples by uroscopists. The needto consider other factors when interpreting urine specific gravity valuesremains as a basic diagnostic axiom today.

Fascinating facts

Did you know that urine is a weak detergent by virtue of its urea content?This detergent property may be greatly enhanced if urine containing largequantities of urea is allowed to undergo bacterial fermentation becausemost of the urea is decomposed to ammonium carbonate, a moderately alkalinesalt.

Urine fermented in this way has been used for thousands of years as asoap, and as an agent to tan and soften hides removed from animals.

In France, during the 17th century wealthy ladies took urine baths tobeautify their skin.

Did you know that in Roman times, urine was commonly used as a mouthwashand prophylactic against dental caries? "Rectified urine," a stronglyammonical solution, was recommended in the 18th century by Pierre Fauchard,the father of dentistry, as a dentifrice and toothache remedy. Romans alsoused urine (the golden liquid) as a flux for soldering gold, and to removeink stains from garments.