Wikipedia:Reference desk/Archives/Science/2020 February 13

= February 13 =

Obesity and failure to drink enough water
Is there a connection between obesity and failure to drink enough water? Freeknowledgecreator (talk) 00:10, 13 February 2020 (UTC)
 * Deletion by consensus at Talk page. DroneB (talk) 00:00, 15 February 2020 (UTC)
 * See and  for example. 73.222.115.101 (talk) 02:07, 13 February 2020 (UTC)

Which medical conditions require the use of blood thinner?
I've previously heard some confidential information that a particular supercentenarian (I'm obviously not going to say which one) could have lived for an additional several days or several weeks had they not been given an incorrect dosage of blood thinner. I've also heard that this blood thinner was given to them in order to deal with an existing medical condition that they had.

In turn, this motivates me to ask--what medical conditions (including life-threatening ones) require blood thinner to treat? Any thoughts on this? 68.96.93.207 (talk) 00:15, 13 February 2020 (UTC)
 * See Warfarin. It's an anti-coagulant, so it's taken to treat conditions (chronic or acute, i.e. long- or short-term) where clotting is a problem. Thrombosis would be a long-term condition, orthopedic surgery such as a hip replacement would be a short-term example. Andy Dingley (talk) 02:17, 13 February 2020 (UTC)
 * I think the most frequent use is in cardiac arrhythmias that predispose to clot formation and emboli. Atrial fibrillation or supra ventricular tachycardia. Also mechanical heart valves. - Nunh-huh 05:59, 13 February 2020 (UTC)
 * What causes thrombosis? 68.96.93.207 (talk) 04:06, 13 February 2020 (UTC)
 * See Thrombosis. HiLo48 (talk) 05:00, 13 February 2020 (UTC)
 * Tangent alert: The term "blood thinner" is the popular name for what is more properly called an anti-coagulant.  I don't think they actually make the blood any thinner, just less likely to clot.  But I would be interested to see actual evidence either way.
 * In Warfarin we find the assertion "While warfarin is one of several drugs popularly referred to as a 'blood thinner'; this is a misnomer since it does not affect the viscosity of blood." However this claim is unsourced, and in any case strictly speaking is only about warfarin, not about anti-coagulants in general. --Trovatore (talk) 06:08, 13 February 2020 (UTC)
 * According to a 1970 study, hemodilution seems to be "the only definite practical method" (available at the time of writing) for lowering blood viscosity. --Lambiam 07:35, 13 February 2020 (UTC)
 * Yes, this is true. "Thinning the blood" is a lie-to-children, or, more politely, an inaccurate metaphor that nevertheless is easier for laypeople to intuitively grasp. "Anti-coagulant" is gibberish to a lot of people. Anti-coagulants work by negatively affecting either the clotting cascade or platelet aggregation. --47.146.63.87 (talk) 03:41, 15 February 2020 (UTC)
 * I know someone middle age who is on long term warfarin after a deep vein thrombosis incident. There was a known family history, and the only other risk factor I'm aware of would be weight. Our article has some limited discussion of such management. Note that using warfarin requires frequent testing to ensure that the patient is at the desired INR level. For an older person, I gather that anticogulants may be used after a cardioembolic ischemic stroke or especially recurrent ischemic stroke in certain circumstances. [//www.nejm.org/doi/full/10.1056/NEJMoa020496][//svn.bmj.com/content/3/2/76] [//www.ncbi.nlm.nih.gov/pmc/articles/PMC6007290/] [//www.nejm.org/doi/full/10.1056/nejmoa011258] [//www.ncbi.nlm.nih.gov/pubmed/9403477] [//www.ncbi.nlm.nih.gov/pmc/articles/PMC6535711/] [//www.ncbi.nlm.nih.gov/pubmed/17239798] As is often the case in medicine, it's a case of balancing what is known or believed about the cause and risks e.g. Valvular heart disease, atrial fibrillation since the side effect is an increased risk of major bleeds so an increased risk of haemorrhagic stroke and other things. And newer anticougulants, especially directly acting oral anticoagulants are changing things.  In reference to the event which inspired this question remember also that if a patient died in 2001, this would be before some of the data. So for example, using warfarin may have been considered reasonable at the time even if it's now considered to not be the case.  As mentioned by Nunh-huh, in patients with an identified atrial fibrillation it may be considered best practice to prescribe anticoagulants to manage the risks from thrombosis (which I think would particularly include stroke but also others like myocardial infarction [//www.nejm.org/doi/full/10.1056/NEJMoa020496] [//www.ncbi.nlm.nih.gov/pmc/articles/PMC5417351/]) even before an identified event, again depending on risk factors (which would include age) [//bpac.org.nz/BPJ/2011/october/af.aspx].  Nil Einne (talk) 11:15, 13 February 2020 (UTC)

My 86 year old aunt has been on rat poison for most of her life due to a hole in her heart. Greglocock (talk) 22:02, 13 February 2020 (UTC)
 * Atrial septal defect? Hmm, I wonder if that's still indicated treatment. From that article it looks like small ASDs generally don't need treatment. I assume if her ASD was significant enough to cause noticeable symptoms, such as cyanosis, it would have been surgically repaired. If she hasn't had her treatment reviewed for a long time, it would be a good idea for her to have a deprescription review, as warfarin treatment has risks (as does any medication of course). For anyone unsure, "rat poison" refers to warfarin, which indeed has been used as a rodenticide. This then caused rodents to develop widespread resistance to it, which means it's seldom used for this anymore; much stronger derivatives are used instead. --47.146.63.87 (talk) 04:39, 16 February 2020 (UTC)
 * The famous mathematician Tim Gowers was diagnosed with atrial fibrillation and was treated first with warfarin, but then with minor surgery (catheter ablation). He wrote about it on his blog.  The trick with warfarin is to get the dose just right: high enough to prevent clotting but low enough to not cause hemorrhaging.  He describes that in his post. 2601:648:8202:96B0:0:0:0:7AC0 (talk) 20:01, 17 February 2020 (UTC)

Unbinding tannins from saliva
I'm looking for references about unbinding tannins from salivary proteins. I can find a lot about binding, causes and effects. I can't find anything on unbinding. Anyone better at searching articles? 135.84.167.41 (talk) 18:46, 13 February 2020 (UTC)


 * There is no good English antonym for the verb bind; some terms that come close are come loose, detach, disconnect, loosen, separate, unfasten. I find some tantalizing hints that low pH can loosen or even undo tannin-protein bounds. especially in the absence of salt. Unfortunately, I mostly run into paywalls or forums where other people are looking for answers, with no guarantee whatsoever of trustability. But this article may be relevant to your search. This article strongly suggests that results for one type of protein should not be generalized to other proteins. --Lambiam 17:54, 14 February 2020 (UTC)
 * "There is no good English antonym for the verb bind" Erm... unbind? Anyway, the closest term to what the OP is looking for is dissociate. Fgf10 (talk) 15:04, 15 February 2020 (UTC)
 * If the binding is reversible, then you could look for a competitive antagonist for binding. If the binding sites are non-specific, then one solution might be to saturate then with a complex mixture of polypeptides (lots of non-specific binding) ... anyone for beef with your astringent red wine? Klbrain (talk) 23:41, 15 February 2020 (UTC)
 * “Displace”?? Also in immunochemistry we often say "wash out" informally. Yanping Nora Soong (talk) 03:28, 16 February 2020 (UTC)

Thanks. With this information, I have been able to find a few papers looking at using specific proteins and fats as agents to unbind tannins from salivary proteins and onto other proteins. Nothing very useful, but at least I'm making headway. 135.84.167.41 (talk) 15:29, 18 February 2020 (UTC)