salvador dali’s beating heart jewel

Over the weekend, I went down to Melbourne to catch up with a couple of my friends and generally wander round the place. On Saturday, I had the pleasure of spending about four hours in the Salvador Dali exhibition at the National Gallery of Victoria. I could probably rant and rave about how amazing that was for some time, but instead I’m just going to post a video of one of Dali’s jewels – the beating heart. It’s made of gold and rubies. The video’s a little blurry, but you get the idea.

hormones and type 1 diabetes

Another repost from my old website. Hope you find it interesting!

Insulin

In the interest of getting a better understanding of the endocrinology behind diabetes, I decided this afternoon to have a poke around the web at information on hormonal glucose regulation.

Type 1 diabetes is fundamentally a disorder of glucose regulation related to the body’s inability to produce insulin. The cells of the body that produce insulin are located in the pancreas in the regions known as the “islets of Langerhans” [2]. In type-1 diabetes, these insulin-producing cells (beta-cells) are destroyed due to an autoimmune response resulting in a dramatic reduction or elimination of the body’s production of insulin.

Since there are a number of glucoregulatory hormones which increase blood glucose levels (including one produced in alpha-cells of the pancreas called glucagon), the absence of insulin leads to a state of hyperglycaemia if untreated. Chronically high levels of glucose in the bloodstream can lead to a number of complications. A lack of insulin in the bloodstream can also lead to diabetic ketoacidosis. Ketoacidosis means the pH level of the blood falls below its normal range due to the acidic effect of ketone bodies in the bloodstream. The reason for the presence of ketone bodies in the bloodstream is related to the body’s mechanisms for handling starvation. Continue reading “hormones and type 1 diabetes”

climate scientists talking climate science

I don’t profess to be particularly well informed on the science of climate change. I read people’s opinions of the science and have read a couple of papers here and there. I guess like many people, I’m reliant on the trust I have in the many, many reputable scientific bodies that have shared their assessments on the matter.

However, I’ve kept seeing in the news lately various claims about the state of scientific consensus on climate change that don’t really fit with the stuff I’ve read directly from groups of scientists. So, while I know this site’s been around for a while and all, I’ve enjoyed reading the opinions of well informed people on the Real Climate blog. It’s good for actually giving some data on oft-raised objections to the science of climate change.

Check it out: http://www.realclimate.org/

the common cold

Another repost from my old website. Hooray!

rossmann.virus.jpegOver the weekend I developed a curious sort of cough. It marked the beginning of my adventure through the common cold. It’s now Thursday and I’m pretty sure I’m on the mend.

It’s most likely that I’m suffering from a viral infection by a type of rhinovirus; a nose-dwelling virus that is responsible for between 25% and 80% of common colds. It’s possible that it could be a coronavirus (10-20%), an adenovirus (~5%) or even some form of influenza (10-15%) [1].

Rhinoviruses (image left – thanks brown.edu) are single-stranded positive sense RNA viruses with an icosahedral capsid constructed from 12 pentameters. An icosahedral structure is one that is constructed a bit like a soccer ball – pentamer structures (5 linked protein monomer units constructed from the 4 viral proteins [2]) form the outside layer of the virus.

You can probably see from the picture that the outside of the virus is not smooth like a soccer ball at all. It has protruding elements that enable the virus to attach to cellular receptors. Rhinoviruses can be grouped into 3 major categories depending on which cellular receptor they attach to: “intercellular adhesion molecule-1 (ICAM-1), low-density lipoprotein (LDL) receptors, and sialoprotein cell receptor” [1].

Can you guess at why it’s called a Rhinovirus? Yup, it’s because it likes to live only in the nose. The virus can survive only at temperatures a little below normal body temperature, from 33’C to 35’C. It also cannot tolerate an acidic environment. This is why the virus infection remains localised to the region called the nasopharynx which is a cavity located behind the nose but above the level of the soft palate. It’s sort of upward a bit from the back of your throat.

Now both you and I know know more about rhinovirus-related common cold infections. Unfortunately my search for a cure led me only to speculations that some ‘mystery ingredient’ in chicken soup ‘might help’. I’m dubious.

[1] http://www.emedicine.com/med/topic2030.htm
[2] http://en.wikipedia.org/wiki/Rhinovirus

noise induced hearing loss

Another repost from my old website. Hope you find it interesting!

Structure of a human ear
Structure of a human ear

Last Thursday I sat at the back of a noisy bus on my way to the station. In my ears were ear buds playing music at my usual fairly moderate level. You can imagine my astonishment then when I realised that I could hear somebody else’s music playing. I took a look around the bus and realised that across the aisle on the other side of another person was a girl listening to thumping techno at volumes that to her must’ve sounded roughly like a 737 landing on her face.

Unlike the irritating clowns who whinge in mX (the free afternoon newspaper distributed on public transport) about iPod listeners’ music distracting them from their furious navel-gazing on their journey home from their dreary jobs, I have no particular problem with being able to hear someone else’s headphones. Since I respect my ears I wouldn’t listen so loud but whatever floats your boat I suppose. Rant aside, it did get me thinking about noise induced hearing loss. So I did a bit of reading, learnt some stuff and hope to enlighten you a little.

The image of the human ear to the right gives a basic overview of what a human ear looks like. Sound waves travel down the ear canal and cause the eardrum to resonate. This vibration is transmitted through the ossicles and into the fluid filled cochlea. Within the spiral-shaped cochlea are a large number of very fine hairs. Their arrangement is somewhat analogous to the keys on a piano where hairs toward one end of the cochlea detect high frequency sound and those toward the other end detect low-frequency sound.
Continue reading “noise induced hearing loss”

paracetamol poisoning

I used to post a bunch of interesting stuff on slightlyodd.com on my old content management system. Sadly, my webhost died and I lost a bunch of articles. However! Thanks to the magic of the internet wayback machine on archive.org, I can repost these articles again! So here we go – the first one on paracetamol poisoning.

paracetamolDuring my hours of productive work today, I noticed an article on smh.com.au about the death of a 33 year-old woman to paracetamol poisoning. I briefly considered how tragic this was but in typical fashion soon began wondering about the medical mechanism of paracetamol poisoning. I’d heard that it’s a particularly gruesome kind of death involving liver failure but wasn’t sure of the details. Off to the net I went!

A tiny bit of background (though you’re probably already quite familiar with paracetamol). Also known as acetaminophen, paracetamol is a condensed name derived from para-acetyl-amino-phenol. It’s an analgesic (painkiller) and antipyretic (used for fever relief). Unlike aspirin or ibuprofen, paracetamol is not an anti-inflammatory drug and is therefore more gentle on the stomach. In therapeutic doses, it is among the safest analgesics in use however the therapeutic dose is quite close to the toxic dose. A typical dose consists of 1 gram, taken no closer than 4 hours apart. Packaging usually recommends against consumption of more than 8 tablets in a 24 hour period.
Continue reading “paracetamol poisoning”