Talk:Chitin

Wiki Education Foundation-supported course assignment

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Shane92z.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 19:01, 17 January 2022 (UTC)

Wiki Education Foundation-supported course assignment

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Student editor(s): Powerforward45. Peer reviewers: Apaltrineri.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 17:34, 16 January 2022 (UTC)

Bioplastic

Chitin can potentially be used as bioplastic. [1] — Preceding unsigned comment added by Ghjgghj (talk • contribs) 01:19, 8 May 2014 (UTC)

Stub

Chitin has been stubbifed.The Fox Man of Fire 00:32, 3 February 2006 (UTC)

Pronounciation

I'm changing it to IPA. Cameron Nedland 02:34, 14 February 2006 (UTC)

Request for expansion

Specifically, chitin's use as surgical thread should be expanded upon. 24.147.141.127 Talk

A few changes

Removed stub tag. Removed sentence "Chitin is considered a type of carbohydrate and is part of the carbohydrates macromolecule.", as it was already stated above in more concise language. Article still needs expansion; chitin is a very important and abundant organic compound. Fuzzform 02:17, 9 April 2006 (UTC)

Fossils

Insects might have depended on fungi to appear, they "helped" plants through symbiosis (mycorrhizas, from Glomaleans related) at the begining. Since Fungi appeared before insects, and are caracterized by chitinous cell walls, i think it might appeared before insects innovation. Moreover, it asks if chitin could have been invented at the begining of Unikont phyla.

Request source

There is no source for the stand alone wound healing statement. —Preceding unsigned comment added by 81.96.193.72 (talk) 22:41, 11 April 2008 (UTC)

Reference 26 from the Chitosan article may be suitable.72.84.162.23 (talk) 04:02, 29 July 2009 (UTC)

Medical Claims and needs for better sources

The source given for chitin as a medicinal tool, Halosource, does not accurately provide a source for this claim. Halosource is an antimicrobial product producer. Additionally, no where in the website linked is chitin mentioned openly. As a researcher, I would hope the author making this claim can provide a more academic source. Luminaux (talk) 12:42, 30 June 2008 (UTC)

FUNGI?

There is probably as much poly n-acetylglucosamine in the form of fungal walls as in the crustaceans and insects...how come there is no mention of this very common source of chitin? For reference, see: http://bugs.bio.usyd.edu.au/learning/resources/Mycology/StructureFunction/wallComposition.shtml Gbrynes (talk) 21:02, 16 October 2010 (UTC)

Is chitin truly the main component of fungal cell walls? I believe that there is a much larger amount of glucans than chitin in the :cell walls of fungi, and there's no source for the claim. I'd change it to read that its an important or unique component of the :cell wall, rather than the main.173.65.160.226 (talk) 16:48, 22 July 2011 (UTC)

Dietary

Is it a digestible polysaccharide, like starch, or an indigestible one like cellulose? —Preceding unsigned comment added by 75.73.70.113 (talk) 00:26, 4 January 2011 (UTC)

Did animals reinvent chitin?

The article currently states that chitin is present in fungi and in some animals; and then that "Chitin first appeared in the exoskeletons of Cambrian arthropods, e.g., trilobites.". Animals and fungi, being opisthokonts, have a common origin separate from other living forms, but had certainly separated before Cambrian arthropods appeared. So the article currently implies that chitin was invented separately by fungi and animals. I doubt that that was the case.

Maybe what is meant is that chitin first appears in the exoskeletons of Cambrian arthropods... In other words, that that is where it is first found in the fossil record; not that that is necessarily when it really first existed.

--David Olivier (talk) 16:51, 21 March 2011 (UTC)

Nice catch! The citation at the end of the paragraph doesn't mention trilobites at all, so presumably applies only to the second sentence. I've changed the problematic sentence to "Chitin was present in the exoskeletons of Cambrian arthropods such as trilobites.", since we don't know for sure there aren't older fossilised chitinous organisms. As far as I know, the actual chitin itself in trilobites hasn't been recovered; its presence is inferred by some other means. Adrian J. Hunter^{(talk•contribs)} 13:43, 22 March 2011 (UTC)

How about changing it to "Chitin first appears in the fossil record in the exoskeletons of Cambrian arthropods such as trilobites."?--Mr Fink (talk) 14:17, 22 March 2011 (UTC)

I'd say Adrian's version is best, if in effect the presence of chitin is inferred rather than found; "chitin first appears" can be ambiguous, suggesting that preserved chitin appears in the remains. --David Olivier (talk) 14:29, 22 March 2011 (UTC)

Good point.--Mr Fink (talk) 15:01, 22 March 2011 (UTC)

Dietary use of chitin?

Didn't chitin used to be sold to bind fats in the stomach so they would not be digested, and sold on late-night infomercials? That's how I heard about it. Maybe something to add. — Preceding unsigned comment added by 38.99.133.32 (talk) 19:07, 19 October 2012 (UTC)

What was influenced by the Greek word?

In the sentence 'These words were derived from the Greek word chitōn, meaning mollusk, that is, influenced by the Greek word khitōn, meaning "tunic" or "frock"', what was influenced by the Greek word khiton? It's not clear to me.--Richardson mcphillips (talk) 01:13, 19 March 2013 (UTC)

Biomedical research

According to the article, "The immobilized protein is purified and released from the beads by cleaving off the chitin binding domain." I don't think that is how it works. I think the protein is released by elution with a solution of chitobiose, the dimer of N-Acetylglucosamine, which competes with the chitin-binding sites. Can anyone with practical biomedical expertise confirm this? Plantsurfer (talk) 11:18, 22 April 2013 (UTC)

Chitin in feathers?

Bird plumage and butterfly wing scales are often organized into stacks of nano-layers or nano-sticks made of chitin nanocrystals that produce various iridescent colors by thin-film interference. This sentence would imply that chitin is a component of bird plumage. Is it corect? --Mirrordor 16:41, 11 January 2014 (UTC) — Preceding unsigned comment added by Mirrordor (talk • contribs)

It is not, there are no evidences of chitin in vertebrates. I will remove that sentence in a week. --Alt1979 (talk) 01:23, 30 May 2014 (UTC)

I rewrote the offending sentence to mention that analogous structures made of keratin are seen in bird plumage.--Mr Fink (talk) 01:48, 30 May 2014 (UTC)

Sounds like chicken?

Chitin sounds quite a lot like "chicken", and if someone said it fast you might end up here instead ed588 (talk) 13:01, 18 July 2016 (UTC)

Source on white than milk or human tooth

https://www.sciencedaily.com/releases/2007/01/070118161742.htm — Preceding unsigned comment added by 76.118.58.163 (talk) 14:31, 24 September 2016 (UTC)

New section on how chitin affects the immune system

Hi Zefr,

You deleted a large chunk of text added to this chitin article with a very brief explanation in the edit summary. I have to disagree with your description that an immune response to chitin is conjecture. The studies quoted in the text are excellent pieces of evidence that we do indeed react to chitin shed by insects such as house mites. You are discarding the work of others just because this is new research and not commonly known. This doesn't make it conjecture as several peer reviewed studies quoted in the section attest. It's suitable for the Wikipedia as it summarises published research and not the opinion of the authors.

Please reconsider this reversal that will just leave readers less informed.

All the best,

--— J.S.^talk 16:15, 14 March 2017 (UTC)

Disagree, J.S.. The encyclopedia reports facts, not preliminary research, conjecture or news per WP:NOTJOURNAL, WP:NOTNEWS. --Zefr (talk) 16:21, 14 March 2017 (UTC)

The WP:NOTJOURNAL you quote merely states that the language should not be the lingo usually found in scientific articles. It does not say no scientific articles should be quoted and summarised. The content you deleted is certainly not news as many of the results were published months or years ago. On the other hand Wikipedia's dispute resolution states that you should not discard text but improve it. So, instead I would invite you to add the research you know that shows that the link between chitin and our immune system is indeed conjecture as you claim. — J.S.^talk 16:39, 14 March 2017 (UTC)

Edited the "Medicine" section to be titled "Research" for which the strongest source support currently is for surgical sutures. If anything is to be added here on the concept of immune responses, it cannot be conjecture or news per WP guidelines as discussed above. In writing for a published journal article, speculation based on the research results is allowed, but that is not the policy of WP as an encyclopedia of known information (i.e., facts). Further, immune responses fall under WP:MEDRS which has stringent requirements for clinical evidence. --Zefr (talk) 16:42, 14 March 2017 (UTC)

The new info should certainly not be added under Uses/Research. Instead it should be under a separate section. The pieces summarized in the deleted section are not speculations from the research articles used. They merely describe the facts discovered by these studies. If you can point out wordings that may look like speculation they should be rephrased by the authors not deleted. The page you quote on identifying reliable sources does actually recommend to use "published secondary sources (such as reputable medical journals)" as was done here. — J.S.^talk 16:54, 14 March 2017 (UTC)

The section under MEDRS described in WP:MEDASSESS states the quality of clinical evidence needed to support possible immune effects, e.g., "The best evidence for treatment efficacy is mainly from meta-analyses of randomized controlled trials (RCTs). Systematic reviews of literature of overall good quality and consistency, addressing specific recommendation, have less reliability when they include non-randomized studies." Further, particularly concerning potential immune effects: "Speculative proposals and early-stage research should not be cited to imply wide acceptance. For example, results of an early-stage clinical trial would not be appropriate in the Treatment section on a disease because future treatments have little bearing on current practice." --Zefr (talk) 17:03, 14 March 2017 (UTC)

The information added was not about treatments. It just summarized the research evidence that there is an immune response to chitin. The Wikipedia has to indeed be careful about treatment and support this with randomized trials. The evidence cited both had proper controls and randomized their subjects. I agree with you that the info added should be clearly separated from anything that could be construed as a treatment. Which parts of the text did you read like this? Those should be reworded or deleted by the authors. The main body of the text referred to how chitin can trigger the immune system without going on to claim that this should influence treatment decisions. I would suggest to add the section again, make clear that it's not about treatment, and improve sentences that you find problematic. Please point those out and explain why. — J.S.^talk 17:54, 14 March 2017 (UTC)

I don't see any of it as usable. The burden is on you or the original editor, WP:BURDEN, to show the content is not conjecture and sources meet WP:MEDASSESS. "Treatment" is not necessarily the issue: it's more about medical/clinical fact vs. speculation. It's not even usable as Research because it's too preliminary, WP:PRIMARY. --Zefr (talk) 18:07, 14 March 2017 (UTC)

• if the discussion is about this series of edits, those were a bit heavy handed but generally dead on. In general all WP content should be sourced to secondary sources, and this is especially true for content about biology; for content about health this is pretty much required per MEDRS. Almost all the stuff Zefr hacked away was based on primary sources. The current content is still pretty poor, confusing ideas published in the scientific literature with actual uses. Rather than waste time arguing about restoring badly sourced content, it would be better to spend time generating well-sourced content. I will try to work on that. Jytdog (talk) 19:36, 14 March 2017 (UTC)

Hi, Jytdog. Thanks for chiming in. I'm not sure how to apply this to basic research or whether it's even a wise choice there. Could you explain the secondary recommendation a bit better here? — J.S.^talk 10:55, 15 March 2017 (UTC)

• Let's look at the some content and see whether the blanket explanation given for the deletion applies:

"Chitin induces the accumulation of innate immune cells" - The statement is well sourced from Reese et al. referring to an oldish 2007 Nature study where chitin attracted immune cells in mice. This is neither conjecture nor news or treatment advice but hard evidence from one of the best and most rigorously checked journals in world.

"These findings are supported by recent studies evaluating polymorphisms in chitinases as a risk for developing asthma." - This statement summarizes a 2005 epidemiological study by Bierbaum et al. that determined that genetic variations in chitin degrading enzymes are reliably correlated with asthma at p<0.01. This is a fact. If you have the chitinase genotype you are more likely although not certain to develop asthma. These association studies is where all medical discovery goes after a basic research discovery.

"Previous studies also indicate that the size of chitin correlates with the immune response" - This summarizes Da Silva 2009 J Immunology where only shorter fragments are seen to trigger a reaction in mouse macrophages. Granted not a study in humans but this is where all medical research begins before it even makes sense to take this to us.

And so on... Heavy handed deletions like the above make the Wikipedia poorer and signal that additions are not welcome. Is this what you want to communicate? — J.S.^talk 11:27, 15 March 2017 (UTC)

J.S.: your examples emphasize their weakness as stock primary research and pure speculation that might be appropriate to give breadth in a journal discussion or textbook, but are not encyclopedic; WP:NOTTEXTBOOK, #6. Primary results speculating about what may apply to human immune function are also not rigorously supported facts verified by well-designed and conducted clinical research per WP:MEDRS. Browse similar examples in the archives of WT:MED by searching for 'primary research'; this has been evaluated dozens of times previously, with the same answer we're giving you here. --Zefr (talk) 15:15, 15 March 2017 (UTC)

• J.S. I started rebuilding the content today. Please feel free to pitch in, using recent reviews or textbooks. There is generally no reason to use primary sources. btw, I am trying to find refs for how chitin is actually used in agriculture and industry. There are no actual medical uses of chtin that I have found (there are medical products on the market that use chitosan but that is not this article). I'll keep looking for refs for a while. Jytdog (talk) 03:14, 16 March 2017 (UTC)

Although one can appreciate the extensive revisions to the Health effects section by Jytdog, the content for humans is still highly speculative about the identity and function of chitin antigens and receptors, and based on only one reference which, for most users including me, is represented only by an abstract. An immune response originating in the GI tract is especially hard to envision without in vivo evidence and is weakly supported in the one source. The receptor evidence is all in vitro WP:PRIMARY research. I've looked for better sources of immune reactions shown in human studies, but they're not available. Overall, weak. --Zefr (talk) 16:19, 16 March 2017 (UTC)

There are 85 reviews in pubmed if you search on <chitin immune> with the review filter on, and 43 of them fall in the 5 year span of WP:MEDDATE. The fact that you cannot access this one (which I chose as it is a very recent MEDRS source) is an invalid objection per the policy, WP:PAYWALL. I will do some more adding of content using additional reviews. Jytdog (talk) 21:44, 16 March 2017 (UTC)

However, this was a good edit. thanks for that. Jytdog (talk) 22:03, 16 March 2017 (UTC)

Hi Jytdog, thanks for the good edits. I think the 2 original student editors will be a little disappointed that very little of their first Wikipedia work made it in but they can also reedit the article with additional information again. — J.S.^talk 11:14, 27 March 2017 (UTC)

What the heck is a lissamphibian?

The opening paragraph links to the lissamphibia page, then cites a source about two amphibians that produce chitin. I changed the link to the amphibian page but it was reverted. Is there a good reason for the less specific and confusing link? 2001:BB6:315F:3658:84E6:3D1B:F519:8DA5 (talk) 08:40, 21 July 2022 (UTC)