Scombroid Poisoning

When there is too much histamine in fish, people should beware.

The Scombroid family of fish includes tuna and mackerel. When stored improperly, there can be too much histamine, which is not degraded by cooking. This causes symptoms of histamine excess, such as urticaria and all the usual culprits of unwellness.

The clinical diagnosis is based on history of multiple people being affected, rather than a single person with an allergy, as well as the redness of the presentation. Theoretically, the fish’s histamine can be measured. Histamine metabolites should show in the urine.

An antihistamine medication is the answer to this issue, such as the H1 antagonist diphenhydramine.

References

  1. Sicari V, Patel P, Zabbo CP. Diphenhydramine. [Updated 2025 Mar 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK526010/.
  2. Liddiard, S., Nickson, C. and Nickson, S.L. (2024). Scombroid Poisoning. [online] Life in the Fast Lane • LITFL. Available at: https://litfl.com/scombroid-poisoning/.

Sharks And Danger

After heavy rain, nutrients flow into harbour waters. This attracts fish that dolphins and sharks like to eat. Therefore, it is not a good idea to swim in public waters within 72 hours after a storm.

Assuming that such urgent swimming is, for some reason, very necessary, there are superordinate principles.

Humans have safety in numbers, because crowds make too much noise for sharks.

If a shark is encountered, look it in the eye. Maybe punch it in the nose, but that is out of the scope of this article.

References

  1. Pepin-Neff, C. (2026). Shark warning: after heavy rain it’s not safe to go in the water. [online] The University of Sydney. Available at: https://www.sydney.edu.au/news-opinion/news/2026/02/05/shark-warning-after-heavy-rain-its-not-safe-to-go-in-the-water.html [Accessed 14 Feb. 2026].

Liquid Fear Antagonist

Alcohol reduces the connection between the amygdala and the prefrontal cortex, so the fear and smart centres don’t communicate as much.

Research people did an experiment, as they often claim to do. It was a suspiciously small sample of participants, as it often is. The difference here was the humanoid laboratory rats being drunk on almost half a litre of alcohol. In fMRI, there was reduced amygdala to prefrontal cortex activity during alcohol intoxication. This suggests reduced connectivity.

Specifically, the decreased amygdala to orbitofrontal cortex interaction messes up the processing and behavioural inhibition around emotional stimuli.

References

  1. Gorka, S. M., Fitzgerald, D. A., King, A. C., & Phan, K. L. (2013). Alcohol attenuates amygdala-frontal connectivity during processing social signals in heavy social drinkers: a preliminary pharmaco-fMRI study. Psychopharmacology, 229(1), 141–154. https://doi.org/10.1007/s00213-013-3090-0
  2. Rolls, E. T., Cheng, W., & Feng, J. (2020). The orbitofrontal cortex: reward, emotion and depression. Brain communications, 2(2), fcaa196. https://doi.org/10.1093/braincomms/fcaa196

Gilbert Syndrome

Spoiler alert! Avoid your eyes if you haven’t seen Kung Fu Panda before. Return to the dark cave from whence you came.

Just as Oogway becomes dust, red blood cells die and puff out bilirubin. This is shunted to the liver, which does the necessary cleaning job, removing the unwanted bilirubin from the bloodstream through glucuronidation. This forms conjugated bilirubin. After Liver Kondo has done its thing, the product is pumped out to the intestines, then away it goes.

Gilbert Syndrome is an autosomal recessive condition where the UGT1A1 gene is most commonly affected. This gene makes an important enzyme for the bilirubin detoxifying process, so the result is raised bilirubin. Specifically, it would be unconjugated hyperbilirubinaemia and possibly jaundice, often not requiring treatment except in stress-affected situations.

References

  1. Mayo Clinic (2025). Gilbert syndrome. [online] Mayo Clinic. Available at: https://www.mayoclinic.org/diseases-conditions/gilberts-syndrome/symptoms-causes/syc-20372811.
  2. Grant LM, Faust TW, Thoguluva Chandrasekar V, et al. Gilbert Syndrome. [Updated 2024 Oct 5]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470200/.
  3. Hamoud AR, Weaver L, Stec DE, Hinds TD Jr. Bilirubin in the Liver-Gut Signaling Axis. Trends Endocrinol Metab. 2018 Mar;29(3):140-150. doi: 10.1016/j.tem.2018.01.002. Epub 2018 Feb 3. PMID: 29409713; PMCID: PMC5831340. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC5831340/.
  4. MedlinePlus (n.d.). UGT1A1 gene: MedlinePlus Genetics. [online] medlineplus.gov. Available at: https://medlineplus.gov/genetics/gene/ugt1a1/.

Xerox In Biology

Circular definitions are a trap. It’s good to avoid traps.

Hence, in simple terms, here are some useful explanations.

Genes are the computer coding for people, because we all know people are actually robots. (Click. Whirr. This is a joke.)

A genotype is the total computer code print-out for a person. It’s relevant to inheritable diseases. A disease is a state of poor health, by the way. It has to be significantly abnormal enough for it to be classed as diagnosable, given these things are based on artificial cut-offs. They can be somewhat arbitrary, but generally there’s a reasonable basis underneath them.

A phenotype is the outside casing of the computer product, which is distinct from its wiring inside. It represents how matters surface in the material world.

A phenocopy is a materialised appearance of things that doesn’t actually have the relevant genotype. That is, it looks like that computer coding output, but the computer coding is different from what it’s expected to be. It resembles a syndrome but without the genetic basis for it.

The phenocopy situation can occur in Huntington’s disease, where the autosomal dominant CAG-repeater mutation isn’t apparent but similar clinical manifestations arise.

References

  1. Moore RC, Xiang F, Monaghan J, Han D, Zhang Z, Edström L, Anvret M, Prusiner SB. Huntington disease phenocopy is a familial prion disease. Am J Hum Genet. 2001 Dec;69(6):1385-8. doi: 10.1086/324414. Epub 2001 Oct 9. PMID: 11593450; PMCID: PMC1235549.

Luria’s Test

Fist, slap, slice! Or fist, cut, slap! Fist, cut, slice?!

It can be tricky to recall the order of Luria’s 3-step test for frontal lobe function.

Here’s a business-minded way to remember it.

GIVE MONEY NOW!

Give

Make a fist.

This represents the aggression of forcing someone to give you something.

Money

Make the slicing motion.

This emulates the handshake of a business deal.

Now!

Slap the hand with the palm facing down.

This is like being a demanding gangster and banging on a table to intimidate your enemy.

References

  1. PsychDB (2021). Luria Sequence (Luria’s Test). [online] PsychDB. Available at: https://www.psychdb.com/neurology/neuro-exam/luria.