Welcome to the pilot episode of our little podcast project. This podcast will evolve over time, but for the moment the thinking is that this space will generally contain show notes. You learn better when concepts are simplified, when you can be totally focused and not worry about jotting things down, etc. By shifting references (etc) to the show notes, we hope to free you of this worry, and allow you to focus on the broader concepts.

The intro portion about engagement and learning references the Yerkes-Dodson law.

The [Scientific American] news article we discussed, “Scientist Who Edited Babies’ Genomes Faces Widespread Criticism” is located [here].

1965 article in Cancer Research, “The Relationship of the Cell Cycle to Tumor Growth and Control of Cell Division: A Review” is located [here]. So you can avoid having to track down this obscure paper, shown at right is the table from the paper that Addie referenced. For the 1990 article, “A nonlinear structured population model of tumor growth with quiescence” here is the [pubmed link] and here is (potentially) a working [PDF link].

The 2006 paper by Katz, “The (Relative) Risks of Using Odds Ratios” is PMID: 16785380 and can also be found [here]. The math on Addie’s RR vs OR examples works out as follows:

8% and 4% → RR of 2 ; OR of 2.09 → [8/92]/[4/96] = 2.09 ≈ 2

80% and 40% → RR of 2 ; OR of 6 → [4/1]/[2/3] = 6

90% and 30% → RR of 3 ; OR of 21 → [9/1]/[3/7] = 21

For the pharma etymologists out there, here is a [drug stem finding tool] that might be useful. It doesn’t get all of the parts of each drug, but it gets some at least. Or you can go straight to the sources and get the [INN] and [USAN] stems!

In our discussion of epigenetics, David Barker was mentioned. Here’s a [1995 BMJ paper from him] entitled, “Fetal origins of coronary heart disease.” Additionally, here’s a [2008 NEJM paper] from Gluckman, et al and the [2007 paper] that Addie mentioned. A [2009 overview] from Gluckman. And a [2009 paper] from Kuzawa and Sweet that talks about epigenetics as a mediator of racial health disparities in America. For good measure, let’s include some recent research → A paper on [birthweight for gestational age] that finds association with specific methylated loci, and a [2017 Nature] paper that looks at genome wide association between adiposity and methylation (higher BMI = more methylation of specific sites).

Regarding toxic mushrooms, Rosen [Emergency Medicine Concepts and Clinical Practice, 2018] says:

“Amanita phalloides mushrooms do not have hallucinogenic properties. Their toxicity is mainly hepatic due to a number of cyclopeptide toxins contained in all parts of the mushroom … Amanita muscaria and Amanita pantherina contain the isoxazole compounds ibotenic acid and muscimol, which are analogues of glutamic acid (excitatory) and γ-aminobutyric acid (GABA; inhibitory) neurotransmitters, respectively.”

Elsewhere Rosen notes:

“It is important to differentiate isoxazole-containing Amanita mushrooms from the deadly hepatotoxic cyclopeptide-containing Amanita mushrooms, of which Amanita phalloides is a member.”

So, to be clear, Addie was correct that α-amanitin containing ‘A. phalloides’ doesn’t make you hallucinate, but Addie was totally wrong in describing it as the ‘Mario Bros’ mushroom → the red mushroom with white dots is probably A. muscaria, and Kim was correct that this causes hallucinations. The species Addie was thinking of is apparently more [white in color].

“The excitatory effects [of isoxazole] characterized by elation, giddiness, hyperactivity, muscle tremors, and distortion of space and time begin approximately 30 minutes to 2 hours after ingestion and are likely to be mediated by ibotenic acid. Following is a phase of tiredness and deep sleep, in which it may be difficult to arouse the patient. During this phase, vivid hallucinations and manic excitement may oscillate with periods of deep sleep. The duration of effect is up to 12 hours,”

…according to Rosen. The other ‘gold standard’ textbook in EM, Tintinalli [Emergency Medicine A Comprehensive Study Guide, 2018], notes,

“Nearly all fatalities in the United States and Europe occur from ingestion of mushrooms of the Amanita species (Amanita phalloides, Amanita virosa, and Amanita bisporigera). If Amanita ingestion is suspected, identification of the species may be helpful but is difficult because there are many Amanita mushrooms that are nontoxic. Amanita species generally have warts on the cap (remnants of the membrane covering the emerging mushroom), which give it a spotted appearance.” Tintinalli also notes, “Nine amatoxins have been identified, but α-amanitin (amanitin) appears the most physiologically active. Amatoxins are not protein bound, but are actively transported into hepatocytes, where they bind to RNA polymerase II and inhibit the formation of messenger RNA. Free radical formation may also be involved in toxicity. In adults, the dose that causes 50% mortality is 0.1 milligram/kg of body weight, which is commonly contained in a single mushroom.”

— Episode credits —

Hosted by Addie, Kim, and Alex. Vocal audio production and editing by Addie. Theme music compositions (Too Cool, and Laserpack) by Kevin MacLeod of incompetech.com, licensed under Creative Commons: By Attribution 3.0 License.