Medicine & Health
edyong | May 4, 2008As fat people have an abundance of fat tissue, the natural assumption is that fat people have more fat cells, or 'adipocytes'. That's only part of the story - it turns out that overweight and obese people not only have a surplus of fat cells, they have larger ones too.
The idea of these 'fatter fat cells' has been around since the 1970s. But their importance has been dramatically highlighted by a new study, which shows that the number of fat cells in both thin and obese people is more or less set during childhood and adolescence. During adulthood, about 8% of fat cells die every year only to…
edyong | May 3, 2008I'm away for the weekend so I thought that I'd repost an article from the old Wordpress blog. This is actually the first ever article I wrote for Not Exactly Rocket Science and I've updated it slightly to take more recent findings into account. I'm considering doing these reposts every Saturday, but let me know whether you're keen on the idea.
Cancer cells are, for all intents and purposes, immortal. Having broken free of the rules and strictures that govern other cells, they are free to grow and divide as they please. In a short space of time, a lone cancer cell can form a mass of…
edyong | April 25, 2008
If it looks like a dead cell and it feels like a dead cell, be careful - it could be a virus. Viruses are experts at infiltrating and exploiting cells but some are so big that they need to use special tricks. The Vaccinia virus is one of these. It belongs to the same family as the more infamous variola virus that causes smallpox. This group are among the largest of viruses, dwarfing many other types by a factor of ten. But despite its size, Vaccinia relies on stealth rather than brute force.
It's a mimic and it disguises itself as cellular flotsam. Vaccinia carries a molecular tag on its…
edyong | April 16, 2008
Of the different types of flu virus, influenza A poses the greatest threat to human health and at any point in time, about 5-15% of the world's entire population are infected with these strains. Together, they kill up to half a million people every year and the death toll rises sharply when pandemics sweep the globe.
Today, two papers published in Nature and Science shed new light on the origins of these epidemics. By prying into the private lives of flu viruses, the studies provide fresh clues about the birthplaces of new strains, their flight plans around the world and the locations…
neurophilosophy | April 16, 2008
On this day in 1943, Albert Hofmann (right), a chemist working for the Swiss pharmaceutical company Sandoz, discovered the psychedelic properties of LSD. Hofmann had actually first synthesized the drug 5 years earlier, as part of a research program in which the therapeutic effects of derivatives of ergot alkaloids - chemicals produced by a fungus - were being investigated.
In his autobiography, LSD: My Problem Child, Hofmann explains how he accidentally ingested the drug while synthesizing it in the laboratory:
It seemed to have resulted from some external toxic influence; I surmised a…
edyong | April 11, 2008For comic book characters, big doses of radiation are a surefire way of acquiring awesome superpowers, but in real life, the results aren't quite as glamorous. A victim of acute radiation poisoning can look forward to hair loss, bleeding, the destruction of their white blood cells and bone marrow, and severe damage to their spleen, stomach and intestines.
Radiation doesn't kill cells directly, but it can cause so much damage that they commit suicide, by enacting a failsafe program called apoptosis. Now, Lyudmila Burdelya and colleagues from Roswell Park Cancer Institute have found a way to…
neurophilosophy | April 7, 2008
A 58-year-old man from Cumbria has had electrodes implanted his brain in order to treat his compulsive gambling.
Raymond Mandale (right), who suffers from Parkinson's, claims that his gambling habit was caused by a prescribed drug he had been taking to alleviate the symptoms of his condition, and is now seeking compensation from the manufacturers of the drug.
Mandale's case is not unprecedented. In the past few months, several Parkinson's patients who began gambling compulsively after taking the dopamine agonist Mirapex have brought lawsuits against the pharmaceuticals companies involved.…
edyong | April 3, 2008Antibiotics are meant to kill bacteria, so it might be disheartening to learn that some bacteria can literally eat antibiotics for breakfast. In fact, some species can thrive quite happily on nothing but antibiotics, even at high concentrations.
The rise of drug-resistant bacteria poses a significant threat to public health and many dangerous bugs seem to be developing resistance at an alarming rate. The headline-grabbing MRSA may be getting piggybacks from livestock to humans, while several strains of tuberculosis are virtually untreatable by standard drugs.
But a startling new study…
neurophilosophy | March 19, 2008
Image: Phisick Antique Medical Collection
This highly detailed papier mache model of the human brain, which can be pulled apart to reveal labelled and numbered structures within, was created by the French physician Louis Thomas Jerome Auzoux (1797-1880).
In the early 19th century, human cadavers for the study of anatomy were in short supply. The dissection of human corpses was difficult, due to the fast rate of decomposition, and also illegal. And the wax anatomical models available at the time were both fragile and expensive.
Taking his inspiration from the childrens' toys sold on the…
neurophilosophy | March 17, 2008
The Sunday Times has an incredible story about Henry Marsh, a consultant neurosurgeon at St. George's Hospital in South London, who travels to a hospital in Kiev twice a year in his spare time to perform free operations using only the most rudimentary instruments:
The young man lies back on the hospital trolley and waits patiently as his head is secured in place with a vice.
Marian Dolishny's nervous smile and worried, flicking eyes, betray the certain knowledge that what he is about to undergo will be anything but pleasant. But he also knows that time is short: if the enormous tumour…
edyong | March 16, 2008
Tropical parasitic diseases may lack the headline-grabbing power of bird flu or SARS and they may fail to grab the pharmaceutical industry's attention. But there is no doubt that they are a massive problem. Schistosomiasis, a disease that many people in Western countries will never have heard of, currently afflicts 3% of the world's population, a staggering 20 million people, and almost four times that number are at risk.
Schistosomiasis, also known as bilharzia, affects people living across the tropics. It's caused by parasitic flatworms called blood-flukes, belonging to the genus…
neurophilosophy | March 13, 2008Best-selling fantasy writer Terry Pratchett, who announced in December that he has a rare form of early onset Alzheimer's, has pledged $1million for research into the disease.
In a speech given ealier today at the Alzheimer's Research Trust Netowrk Conference in Bristol, Pratchett said that he compliments his conventional treatment with various unspecified alternative remedies, in the hope that he can slow the progression of the illness:
The NHS kindly allows me to buy my own Aricept because I'm too young to have Alzheimer's for free...But, on the whole, you try to be your own doctor. Teh…
neurophilosophy | March 12, 2008
(AP Photo/Greek Culture Ministry, HO)
This skeleton, exacavated recently in the town of Veria, some 75km west of Thessalonika, provides evidence that the ancient Greeks performed sophisticated neurosurgery.
The remains, dated to the 3rd century A.D., belong to a woman aged around 25, who appears to have died as a result of a failed craniotomy which was performed to treat a severe blow to the crown of the head.
The large hole above the eyes is precisely cut, suggesting that the skull was perforated with specialized instruments and not a sharp stone.
neurophilosophy | March 12, 2008Thanks to Natasha Dantzig for drawing my attention to this talk from last month's TED Conference in Monterey, California:
Neuroanatomist Jill Bolte Taylor had an opportunity few brain scientists would wish for: One morning, she realized she was having a massive stroke. As it happened - as she felt her brain functions slip away one by one, speech, movement, understanding - she studied and remembered every moment. This is a powerful story about how our brains define us and connect us to the world and to one another.
Taylor describes her experience in terms of unlocking the hidden potential…
neurophilosophy | March 3, 2008
[Introduction|Part 2|Part 3]
The study by McKemy et al is of great significance, as it led to the identification and characterization of the first cold receptor. This study also suggests that TRP channels have a general role in thermosensation, as all the previously identified TRP channels are sensitive to heat.
Dhaka et al (2007) show that TRPM8 is required for sensitivity to innocuous cool stimuli and is also involved in sensing noxious cold temperatures. The TRPM8 knockout mice generated in this study have only a partial deficit in sensing noxious cold stimuli, so it is most likely that…
neurophilosophy | February 27, 2008[Introduction]
McKemy et al (2002) used whole-cell patch clamping and calcium imaging to record the responses of cultured rat trigeminal ganglion neurons to cold temperatures and various cooling compounds. They found that the cells respond to menthol and cold with an increase in intracellular calcium ion concentration, and that these stimuli activate non-selective cation channels which are highly permeable to calcium. The currents measured were also found to be outwardly rectifying (i.e. much larger at positive than at negative holding potentials). Similar results were obtained from DRG…
neurophilosophy | February 26, 2008A few days ago, I briefly discussed the article by Oliver Sacks about geometric hallucinations in migraine aura. I thought that it was published in the print edition of the New York Times, but it turns out that this is in fact Sacks's first post on a new NY Times blog called Migraine: Perspectives on a Headache.
Sacks is one of five "migraneur" contributors to the new blog. (His co-bloggers are author Siri Hustvedt, journalist Paula Kamen, neurologist and psychiatrist Klaus Podoll and musician Jeff Tweedy.) The post/article about visual migraines generated a lot of discussion, and, in his…
neurophilosophy | February 25, 2008
The Lobotomist, a PBS documentary about Walter Freeman which I mentioned recently, is now available online as a series of short clips that require either QuickTime or Windows Media Player for viewing.
The program charts how the lobotomy came to be regarded as a cure for most types of mental illness, how Freeman "refined" the procedure, and how, in the face of criticism, it was eventually replaced in the 1950s by the newly-developed neuroleptic drugs.
Read more about the rise and fall of the prefrontal lobotomy, and watch a film clip of James Watts and Walter Freeman performing a prefrontal…
neurophilosophy | February 22, 2008
In an article called Patterns, published in the NY Times earlier this month, neurologist and author Oliver Sacks discusses the geometric visual hallucinations which occur during the migraine auras that he has experienced since early childhood.
Sacks explains that the hallucinations occur as a result of waves abnormal electrical activity sweeping across the visual cortex, and that they reflect the cytoarchitectonics of that part of the brain and the complex patterns of activity within it.
He goes on to speculate that, because this cellular activity is universal, it forms the basis of art and…
neurophilosophy | February 19, 2008Here's some fascinating footage from 1942, showing Drs. James Watts and Walter Freeman performing a prefrontal leucotomy. The footage accompanies a short article called Lobotomy Revisited, and, like last week's trepanation film clip, is not for the squeamish.)
The procedure shown in the film is the Freeman-Watts Standard Procedure, which had been in use since 1936. This is different from the "ice-pick" lobotomy, which Freeman began to perform in 1945; it more closely resembles the original procedure of the Portugese neurosurgeon Egas Moniz.