On April 29 of 2017, I posted in this blog about a Wikipedia mystery. The mystery concerned a chemical reaction linking the processes of glycolysis, where sugars are converted to a metabolite called pyruvate, and the Krebs Cycle, where pyruvate is oxidized to carbon dioxide and water, producing the majority of the energy that most living things use. This linkage involves a reaction which contains a step where a molecule of carbon dioxide is removed from pyruvate in a process called “decarboxylation”. I found that this pyruvate decarboxylation step was named the “Swanson Conversion” in a Wikipedia page dealing with this subject. The problem was that nowhere in the biochemical literature was there any mention of this metabolic step using that name.
In another post, I wrote about the solution to this mystery. Andreas Kolbe, who posts on Twitter under the handle “Wikiland”, contacted me to let me know that he had found the perpetrator of the hoax. Apparently a high school teacher named Swanson referred to this particular metabolic step in his classes as the Swanson conversion to help his students learn its importance in the whole process. One of his students then decided to edit a Wikipedia article naming this reaction “The Swanson Conversion”. When the teacher found out about this edit, rather than notify Wikipedia, he decided to use this occurrence as an experiment to see how long it would be before it got detected. He also presented this as an example to his students of how you have to be cautious when using Wikipedia.
According to Wikipedia, the hoax remained in the Wikipedia page dealing with pyruvate decarboxylation for 6 years and 6 ½ months, and they quote one of my posts to explain the edit removing the term “Swanson Conversion” from the page. While this hoax holds the record for the longest that a chemistry/biochemistry hoax has survived in Wikipedia so far, it is by no means the longest hoax. There are 85 detected hoaxes in Wikipedia that have lasted longer than the Swanson Conversion, with the longest hoax (the claim that “Vivarem” is a Sanskrit word) surviving 12 years and 9 months before being detected.
Wikipedia hoaxes have made their way into newspapers and academic publications, only to then be quoted by Wikipedia in support of the hoax in a process that has been humorously termed “citogenesis” or more formally “circular reporting”. Because of this, I was interested in investigating whether this hoax had made its way into mainstream science. In my previous post, I mentioned that I had found at least one scientific article that included the hoax.
A Single Regulator Mediates Strategic Switching between Attachment/Spread and Growth/Virulence in the Plant Pathogen Ralstonia solanacearum by Khokhani and coworkers was published in the journal mBio in 2017.
The mention appears in the “Results” section of the article:
“The low-cell-density-mimicking strain also upregulated genes involved in fatty acid metabolism, such as the Swanson conversion of pyruvate to acetyl-coenzyme A (acetyl-CoA), acyl-CoA dehydrogenases and acetyltransferases, and the trifunctional enoyl-CoA hydratase/ delta3-cis-delta2-trans-enoyl-CoA isomerase/3-hydroxyacyl-CoA dehydrogenase that catalyzes the -oxidation of fatty acids (Fig. 3).”
Since then, I have found 2 additional articles that contain the hoax.
Understanding the microbial basis of body odor in pre-pubescent children and teenagers by Lam and coworkers published in the Journal Microbiome in 2018.
The mention also appears in the “Results” section of the article.
“In an independent pathway, enzymes involved in oxidative degradation of pyruvate aliphatic carboxylates to acetyl-CoA (Swanson Conversion) in a process that is key to the production of acetic acid and sour odor were found to be malodor-associated in S. epidermidis (Fig. 3d; e.g., pyruvate dehydrogenase (EC:22.214.171.124)).”
Dissecting the transcriptional networks underlying the gibberellin response in Nicotiana tabacum by Manoharlal and coworkers published in the journal Biologia Plantarum in 2018.
The mention appears in the “Results and Discussion” section of the article (note: this article is not freely available online).
“A pyruvate dehydrogenase complex (a PDHC-E3 subunit, dihydrolipoyl dehydrogenase) catalyzes the conversion of pyruvate to acetyl-CoA by pyruvate decarboxylation (Swanson conversion), thereby paving the entry of pyruvate into the TCA cycle, was observed to be significantly down-regulated (RFC = -3.81).”
Apart from these 3 articles, I also found 2 patent applications that include the hoax.
Methods of selecting subjects for treatment with metabolic modulators by David Kolb filed in 2017
“The pyruvate dehydrogenase complex facilitates conversion of pyruvate into acetyl-CoA by pyruvate decarboxylation (Swanson Conversion) thus linking the glycolysis metabolic pathway to the citric acid cycle.”
Pharmaceutical Compositions Affecting Bioenergetic Processes in a Eukaryotic Biological System and Methods of Treatment by James Sheehan filed in 2016
“Acetyl-CoA is produced during cellular respiration during the Swanson Conversion, which takes place in the mitochondria of eukaryotic bioenergetic systems.”
The hoax has also made it into the webpage of at least one corporation. The company BOC Sciences, which sells chemical and biological products, includes the hoax in a webpage describing one of its products.
The pyruvate dehydrogenase complex contributes to transforming pyruvate into acetyl-CoA by a process called pyruvate decarboxylation (Swanson Conversion).
As you can see, these descriptions mention the Swanson Conversion as if it were established science without even quoting a reference to justify the name. If this hoax had not been detected and removed from Wikipedia, some of these references could have been cited in support of the hoax closing the circular reporting (citogenesis) loop. Another interesting aspect is that although the hoax was introduced in 2010, the earliest mention I have found so far of the hoax in the mainstream scientific literature is the patent filing from 2016. This may indicate that several years are required before a Wikipedia hoax enters the scientific literature, or that during this time frame scientists acquired the mentality that it’s acceptable to use Wikipedia as a source, or that the hoax was taught to science students as fact (see below).
There is also the question of how the Swanson Conversion hoax made its way into mainstream science. I can imagine two ways:
1) When scientists without a very in depth knowledge of the topic (and no one can be an expert in everything) took the information directly from Wikipedia or from a source that mirrors or quotes Wikipedia.
Although this mistake is not excusable, it is understandable. The technical literature seldom contains readily accessible repositories of the most basic information presented in a straightforward way for every topic. The temptation is always there to save time and accept the abbreviated information provided by Wikipedia or related sites without consulting additional literature.
2) When students who have been taught the hoax advance in a career in the chemical or biochemical sciences and are asked to contribute to write parts of scientific articles or other documents.
These students may go back to check their old study notes and end up perpetuating the hoax. In my first post about the Swanson Conversion hoax, I mentioned that several websites featuring the hoax provide study support for students in the form of study sets, lectures, flash cards, mock exams, and even videos. Many students were and are still being educated with the notion that this hoax is true.
As you can see Mr. Swanson’s high school experiment is still ongoing, and it has made the transition from a mere Wikipedia entry into mainstream science. Now that the hoax has been exposed and deleted from Wikipedia, will that stop its spread? How far will the Swanson Conversion infiltrate the scientific establishment? How long will it go? Stay tuned and I will keep you posted!
A while ago I was surprised to read in Wikipedia that the decarboxylation step of the reactions of the pyruvate dehydrogenase complex, which connects glycolysis to the Krebs Cycle, was referred to as the “Swanson Conversion”. Even though I had been trained as a biochemist, I had never heard about this before. So I did some research, and I was not able to find any references regarding a doctor Swanson who was involved in the study of this chemical reaction. I did, however, find a claim that stated that a high school teacher named Swanson, who wanted something named after him, instructed his students to insert this claim in Wikipedia.
I published a post in my blog that was critical of this hoax, and as a result of this the term “Swanson Conversion” was dropped from the Wikipedia page where I found it, although it can be still found in several sites that mirror or quote Wikipedia. But I was still curious if the story about the high school professor was true. Well, thanks to some sleuthing by Andreas Kolbe, who posts on Twitter under the handle “Wikiland” the mystery has been solved. The edit was made in 2010, and he traced the IP address involved in the edit of the Wikipedia Pyruvate Dehydrogenase page to a school and found that in that school there was a teacher named Swanson. Kolbe proceeded to contact the teacher (I will not be revealing the name, location of the school, or the first name of the teacher).
According to the teacher, he was following a textbook that mentioned the different steps of energy metabolism; glycolysis, Krebs Cycle, and electron transport chain, but then the book went on to state that four steps were involved without specifically naming the fourth step. He then decided to christen this fourth step (the chemical reaction linking glycolysis to the Krebs cycle) after himself to help his students learn its importance in the process. Later he found that one of his students had, without his consent, introduced the term into Wikipedia. The teacher then decided that he would let the term linger there as a social experiment and point it out to each of his new classes of students as an example of the perils of using Wikipedia as a reference source.
As it turns out the Swanson Conversion hoax has been one among many hoaxes to plague Wikipedia. Several of these hoaxes eventually get referenced by non-Wikipedia sources leading to a process humorously called “citogenesis” (or more formally “circular reporting”) where the non-Wikipedia sources that originally copied the information from Wikipedia get referenced by Wikipedia itself as proof of the validity of the information! There are several well-documented instances of citogenesis in Wikipedia.
In the case of the Swanson Conversion, although the hoax lingered for about 7 years, only recently did I find an example of the term making it to a mainstream scientific publication indexed in the NCBI (National Center for Biotechnology Information) PubMed database. Thankfully, I was able to detect this hoax before the circle was closed and a new “citogenesis” event took place.
As to Mr. Swanson, I am told that he is a very good and fun teacher who inspires his students, has won a prestigious teaching award, and has used this example of a bogus Wikipedia entry to instruct his students on the perils of using this database. I do hope, however, that in the future he is more proactive about calling out these hoaxes.
Image reproduced here under a Creative Commons Attribution-NonCommercial 2.5 License.
In scientific research it often happens that significant discoveries or methodological advancements get christened after the person who made them. For example, the process by which we treat milk in order to reduce harmful bacteria is called pasteurization after the French Biologist Louis Pasteur. The fecal bacterium E. Coli (Escherichia Coli) is named after its discoverer: Dr. Theodor Escherich. The sequence of reactions involved in generating most of the energy that cells use is called the Krebs cycle after the British biochemist Hans Krebs. Even pieces of laboratory glassware are named after people! The Erlenmayer flask is named after the German chemist Emil Erlenmeyer, the Dewar flask is named after the Scottish chemist James Dewar. The Büchner flask is named after the German chemist Ernst Büchner.
The field of science that has assigned more person names to entities is chemistry. There are hundreds of reactions in chemistry that are named after the researchers who discovered or studied them. There are reactions such as the Birch reduction (after the Australian chemist Arthur Birch), the Wohl degradation (after the German chemist Alfred Wohl), the Robinson annulation (after the English chemist Robert Robinson), and countless others that meander the nightmares of chemistry students worldwide before exams.
Today I am going to write about a curious chemical reaction that I encountered. I was reading about an enzyme called pyruvate dehydrogenase (PD). This enzyme is part of the PD complex which is responsible for the conversion of the substrate pyruvate (an end product of carbohydrate metabolism) into another substance called Acetyl-coenzyme A, which is one of the first substrates of the Krebs cycle mentioned above. The PD complex is important for many reasons. For example, head trauma can lead to a reduction in the levels of this enzyme which compromises the energy state of the nerves and can lead to neuronal death.
I was trying to search for a fact about PD without having to wade through countless pages of erudite reviews, so I quickly Googled “pyruvate dehydrogenase” and among the hits was a Wikipedia entry. So, even though I am mindful of the perils of using Wikipedia, I (mea culpa, mea culpa, mea maxima culpa…) clicked on the Wikipedia page of pyruvate dehydrogenase. To begin the conversion of pyruvate to acetyl-coenzyme A, this enzyme carries out the decarboxylation of pyruvate, whereby carbon dioxide (CO2) is removed from the molecule. What caught my attention is that this process, the decarboxylation of pyruvate, was referred to as the “Swanson conversion”. I thought this was odd. I did not remember ever reading this during my education as a biochemist or in my whole professional career thereafter. I found a Wikipedia entry that cited a link from the Rensselaer Polytechnic Institute to justify naming this reaction in this way. But this link did not have any such information. I checked my old biochemistry books, and there was no mention that this process is called the Swanson conversion. Who was Dr. Swanson and when did he/she perform the research on the decarboxylation of pyruvate?
I checked the scientific databases. The PubMed database has no entries regarding the Swanson conversion. Also, although this database has 1068 entries regarding pyruvate decarboxylation, none of them are associated with anyone named Swanson. Switching the term of the search to “pyruvate dehydrogenase” yields 18,080 hits of which only 8 are associated with a person named Swanson, but none of these articles are specifically about this mechanism. I performed searches with Google Scholar, Science Direct, and WorldWideScience but no luck either. None of these or other bona fide science websites seemed to have any mention of the Swanson conversion or of the pioneering work of Dr. Swanson on pyruvate decarboxylation that led to this process being named after him or her.
I then proceeded to google “Swanson conversion” along with the term “pyruvate” (to eliminate from the hits religious conversions experienced by people named Swanson and conversions (as in scoring) by sport players named Swanson). I came up with 687 results. These hits include entries in sites like the World Heritage Encyclopedia, the World Library, and in the Chemical Entities of Biological Interest (ChEBI) website, which is associated with the European Bioinformatics Institute (EMBL-EBI). I also found entries in study websites in the form of study sets, lecture and exam flashcards, and even an AP video. There is a generation of students out there who is learning that the pyruvate decarboxylation step of the pyruvate dehydrogenase reaction is named the Swanson conversion!
As I was going over the links to webpages that mentioned the Swanson conversion, I noticed that many of them where either from Wikipedia or contained or referenced Wikipedia content. Finally in the website “Answers.com” I found the following unsettling claim:
“The Swanson Conversion is another term for Pyruvate Decarboxylation. It is part of the process by which cells produce ATP and takes place before the Krebs Cycle. The origin of the name "the Swanson Conversion" is unknown, but the story goes that there was a high school biology teacher named Swanson who wanted something named after himself, so he told his students to put "the Swanson Conversion" down as another name for pyruvate decarboxylation on its wikipedia page and spread the name around the internet to gain it credibility, and now the name is commonly used as a substitute for "pyruvate carboxylation".
Of course, I have no way of knowing if this is true, but it would be consistent with the apparent lack of information regarding this topic. And if this was a joke, it seems to have caught on. Eight of the google hits I obtained also claimed that the Swanson conversion is also known as the “Naypyidaw Reaction”. One even called it the “Metallica reaction”.
I don’t know if the people responsible for this will one day come out (like the jokesters who made the crop circles in Britain or the ones that faked the iconic photograph of the Loch Ness monster) to alert the world of its gullibility and the perils of online sites, but I am a bit miffed by this occurrence. Scientists devote their lives to grueling research that more often than not produces dead ends, anxiety, and depression. Along the way there are small victories and the pleasure of small discoveries, but sometimes with the right mix of genius, vision, and luck a scientist discovers or achieves something important enough to have an impact on society and to be associated with their names. I consider this joke to be a slap in the face of these generations of scientists that have made and still are making the world a better place.
Update 10-22-17: The mystery of the Swanson Conversion has been solved!
Image of Pyruvate Dehydrogenase Complex Reaction by akane700 (CC BY-SA 3.0).