24.12.06

Teh Gross: Pork farms

Um, let's see. There's this article that I recently read in Rolling Stone about American swine farms. Here's an excerpt:

Taken together, the immobility, poisonous air and terror of confinement badly damage the pigs' immune systems. They become susceptible to infection, and in such dense quarters microbes or parasites or fungi, once established in one pig, will rush spritelike through the whole population. Accordingly, factory pigs are infused with a huge range of antibiotics and vaccines, and are doused with insecticides. Without these compounds -- oxytetracycline, draxxin, ceftiofur, tiamulin -- diseases would likely kill them. Thus factory-farm pigs remain in a state of dying until they're slaughtered. When a pig nearly ready to be slaughtered grows ill, workers sometimes shoot it up with as many drugs as necessary to get it to the slaughterhouse under its own power. As long as the pig remains ambulatory, it can be legally killed and sold as meat.
Yeah. Totally gross.

Of the four antibiotics mentioned in the article, only oxytetracycline is used in human medicine to prevent/treat bacterial infections. This drug is produced by a soil bacterium (Streptomyces rimosus) and was first isolated in 1953. Tetracyclines are broad-spectrum (work against a wide variety of bacteria) and do their thing (inhibiting the growth of bacteria) by reversibly binding to ribosomes (protein manufacturing centres found within cells) and inhibiting the production of bacterial proteins. Oxytetracycline is particularly awesome because it is used to treat bacterial infections affecting honey bee larvae.

Draxxin is actually a trade name for a drug called tulathromycin, which belongs to a new subclass of macrolide antibiotics (the best known drug of this class is erythromycin, mechanism of action is inhibition of protein synthesis) and is used primarily to prevent/treat SRD and BRD (swine/bovine respiratory disease, a broad term encompassing fun things like pneumonia). Apparently an entire treatment course can be administered by a single subcutaneous (under the skin) injection.

Ceftiofur is a broad-spectrum cephalosporin, meaning that it acts in a similar manner as penicillin, inhibiting the construction of an important component of the cell walls of bacteria called peptidoglycan. Ceftiofur, like tulathromycin, is administered solely by injection (intramuscular, or into a large muscle, in this case) and is mostly used to treat respiratory disease in cows and pigs.

Tiamulin is a broad-spectrum pleuromutilin that is is injectible (intramuscular), slows bacterial growth by inhibiting protein synthesis, and is particularly good at inhibiting the growth of bacteria belonging to the genera Brachyspira and Mycoplasma. Mycoplasma are nifty because they don't have a cell wall, a thing most other bacteria are in possession of.

A trend worth noting: most (and possibly all) of these antibiotics are broad-spectrum and administered by injection. Which makes sense, since you want to be able to prevent/treat as many types of bacterial infections as possible and have a relatively convenient method of doing so. The problem with this approach is that it selects for the survival of numerous strains of bacteria that are resistant to the drugs being used. Ick.

http://en.wikipedia.org/wiki/Oxytetracycline

18.12.06

α-Latrotoxin

  • neurotoxic (bad fer teh brain) protein present in the venom of widow spiders (members of the genus Latrodectus) including the infamous black widow
  • one of seven latrotoxins, is the only one that is vertebrae-specific (only affects animals with a spine, so my chemistry prof should be safe! OH SNAP!), the others being primarily active against insects (the natural prey of the spiders) or crustaceans
  • the current theory is that four units of the protein can join together to form pores in cells, with the resulting changes in ion flux signalling the release of neurotransmitters from nerve cells, producing (among other things) muscle contraction, manifested as painful abdominal cramps and breathing difficulties
http://en.wikipedia.org/wiki/Latrotoxin
http://en.wikipedia.org/wiki/Latrodectism

16.12.06

Teh Busted: Trey Anastasio

Trey Anastasio was arrested yesterday and charged with several offences including possession of a controlled substance. In actuality, he was found with at least three such substances: hydrocodone, Percocet (oxycodone) and Xanax (alprazolam)

Now, I am not a Phish fan, but my good friend Chris is. So permit me to explain why Mr. Anastasio might have been interested in taking the aforementioned drugs, even while operating a black 2004 Audi sedan at 3:30 in the morning in Whitehall, New York:

  • Firstly, they are all addictive. So if Trey had previously given them a go, he might have got himself hooked.
  • Secondly, they all make you feel pretty darn good. Hydrocodone and oxycodone are opioid analgesics derived from codeine (the good stuff in Tylenol 3s) and morphine, respectively, two drugs that are present in opium. Although codeine isn't nearly as potent a drug as morphine, hydrocodone was designed with increased potency in mind, so they'll both dope you out pretty darn well. Alprazolam is a benzodiazepine used primarily as an anxiolytic (treats the symptoms of anxiety), but in higher doses it can produce sedation (it calms you down and chills you out).
  • Thirdly, they are all available as pills, making them easier to administer than other addictive drugs such as heroin.

11.12.06

Nepetalactone - Kitty in the sky with diamonds

100% Pure Catnip by Cosmic Pet

  • psychedelic present in catnip (Nepeta cataria) that causes cats to party hearty (sniffing, rolling around, rubbing their chin against things, etc.)
  • unusual since most psychotropic drugs (those that act on the brain) affect a wide variety of mammalian species (this drug only appreciably affects cats)
    • causes a mild buzz in humans
  • only works by inhalation, feeding cats the plant in an encapsulated form (as a pill) produces no effect
  • is a terpenoid, a class of aromatic (as in they have a scent, not a benzene ring) chemicals that include menthol, camphor and the cannabinoids (THC baby!)
  • insect repellent and aphid sex pheromone (besides the inherent awesomeness of this, it also enables the drug to be used to promote the spread of aphid diseases as a green alternative to using insecticides)
Perrine, Daniel M. The chemistry of mind-altering drugs: history, pharmacology, and cultural context. Washington, DC: American Chemical Society, 1996.

1.12.06

Phenytoin

And now for something completely different. Epilepsy is a relatively common neurological disorder that features recurring spontaneous seizures. Most people associate seizures with muscle spasms (someone convulsing on the floor), but these periods of overactivity in the brain can also present in as benign a manner as loss of contact with the environment (spacing out) for a few seconds. It all depends on the type of seizures that people have. Many people with epilepsy can be effectively treated (have their seizures controlled) using antiseizure drugs, otherwise know as anticonvulsants or antiepileptics. As one of my profs has pointed out, both are pretty lousy names, since not all seizures cause convulsions and antiepileptics sounds like they are intended to knock off people with epilepsy. Which they are not.

Anywho, one of the classic big drugs that has been and continues to be used in the treatment of epilepsy, in particular those people who have tonic-clonic (grand mal) or partial seizures, is phenytoin. Here are some things about it:

  • aka Phenytek, Dilantin, Epanutin
  • introduced in 1938 to much hooplah since it was less sedating than barbiturates (e.g. phenobarbital), which were the only good antiseizure drugs available at the time
  • has a long half-life (~22 hours), which means that it only has to be taken once per day
  • has oodles and fadoodles of terrible side effects, which include: gingival hyperplasia (your gums grow way huge and can easily become infected, potentially causing you to lose all of your teeth), hirsutism (lots and lots and lots of body hair), acne, sedation, and stomach upset
  • is teratogenic (causes birth defects), although it is interesting to note that untreated epilepsy also increases the risk of birth defects