Urine is not sexy—to most people, at least.
The mere word (or any of the myriad synonyms) will generally elicit some level of distaste—it is, after all, a waste product. Sure, most animals use it in some form of communication, generally to mark their territories. One could argue that partially because of this, however, we have developed an aversion to the liquid, and, no longer useful in this way, it clearly must be discarded. The odor and toxicity certainly don't help its case, either.
However, as most people already know (though not all might be ready to admit), this is simply not true.
The amount of information hidden in away in this waste product can be astonishing. Urine contains a wealth of biomarkers, from simple ion counts, to various peptides, to certain viral DNAs. Last time in our Amazing Samples blog series, we discussed antibodies: this time let’s talk about how urine (an unsung hero?) can be a truly Amazing Sample.
The Egeland Family and PKU
Today, most developed countries screen newborns for phenylketonuria (PKU), a genetic inability to metabolize a specific essential amino acid (phenylalanine). While debilitating when untreated, PKU is easily managed with some basic nutritional guidance. For individuals with PKU, simple dietary restriction and supplements mean the difference between normal daily functions and nigh-complete incapacitation. And our awareness of this genetic disease is all thanks to urine.
You see, in Norway in the 1930’s, Borgny and Henry Egeland were at their wits’ ends with their children’s condition: six-year-old Liv was barely speaking and only walking with great difficulty; four-year-old Dag was doing neither. Borgny had taken her two children to specialist after specialist, but no one could provide any rhyme or reason to their situation, other than the dismissive diagnosis of “feeblemindedness”. But then, Borgny visited a well-known doctor, Dr. Følling, who pursued a specific part of the mystery. The Egelands had noticed that their children’s urine had a strong, unusual odor, and after conducting extensive chemical analysis, Dr. Følling not only discovered that the odor came from a substance not normally found in urine (phenylpyruvic acid), but also recognized that it resulted from a metabolic disorder. If not for this rigorous investigation of what was otherwise just “waste product”, children around the world would have continued to be falsely diagnosed with some type of neurological condition instead of a treatable metabolic condition. Read more on Dr. Følling's discovery, and the development of the treatment, on Chemical Heritage Foundation's website.
Medulloblastoma Biomarkers in Urine
Drs. Edward Smith and Michael Klagsbrun recently published a paper in Cancer Research that established a link between urine levels of the protein netrin-1, and medulloblastoma—the difference between the cancer patients and the control group was nine-fold. Since medulloblastoma is an unfortunately common brain tumor in children, having a completely non-invasive diagnostic tool for this condition is an incredible asset to the children's psychological well-being. However, this is not the only significant result of their research—after all, many biomarkers in any number of bodily fluids might indicate the presence of cancer. Smith and Klagsbrun, though, also discovered that the netrin-1 protein serves an integral function in the spread of the tumor: more invasive tumors were found to correlate with even higher levels of netrin-1. Their discovery will both enable oncologists to prioritize patients in more danger, and also provide a means of decreasing the tumors’ invasiveness, as their research also found that targeting the protein can inhibit the tumors' growth. Read more about their paper, and some history of how they got there (it involves more than a little studying of urine), on the Boston Children’s Hospital’s blog.
Ebola RNA… in Urine?
With the ongoing Ebola outbreak, many people are rushing both to develop vaccines and improve treatment, as well as to understand specific characteristics of the virus. Given the high number of patients desperately needing treatment in West Africa, allocation of sufficient resources for research in those areas is not yet possible. However, the two patients in the United States and the single patient in Germany have allowed detailed observations, including an interesting and unexpected discovery with regard to the patient in Germany. He was released after his symptoms resolved, and his plasma showed no viral RNA after his recovery. However, viral RNA could be found for weeks afterwards in both his urine and sweat. Historically, patients have not been found contagious when their blood is free of the virus, so the significance of this discovery is still uncertain, but it’s possible that urine might provide new insight into this terrible illness. Read The New England Journal of Medicine’s editorial to find out more.
From just these stories, it’s clear that urine continues to offer a wealth of information to researchers. As they say, One Man’s Trash Is Another Man’s Treasure.
Are you working with urine samples right now? Please use the comments section below to share your story, and discuss how urine is an Amazing Sample!
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