viruses
mikethemadbiologist | September 30, 2009One of the thing we need to pay attention to during TEH SWINEY FLOO! is the role of bacterial infections in flu-related mortality: a fair number of the deaths ultimately could result from a secondary bacterial infection by organisms like Staphylococcus (including MRSA), Streptococcus, and some of the Gram-negative organisms. Unfortunately, this is happening in a significant fraction of cases:
Nevertheless, the 22 cases (among 77 deaths confirmed to be from H1N1) emphasize that bacterial co-infections are playing a role in the ongoing pandemic, something that was not clear at first, the CDC…
edyong | September 18, 2009The two-toed sloth is a walking hotel. The animal is so inactive that its fur acts as an ecosystem in its own right, hosting a wide variety of algae and insects. But the sloth has another surprise passenger hitching a ride inside its body, one that has stayed with it for up to 55 million years - a virus.
In the Cretaceous period, the genes of the sloth's ancestor were infiltrated by a "foamy virus", one of a family that still infects humans, chimps and other mammals today. They are examples of retroviruses, which reproduce by converting an RNA genome into a DNA version and inserting that…
edyong | September 14, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science.
It's not just us who like to go travelling in the summer - flu viruses do it too. After a busy winter of infection, they turn into the gap-year students of the virus world. They travel round the world, meet new viruses, swap genetic material, and returning back, changed and unrecognisable (at least to our immune systems).
The success of flu viruses hinges on their ability to rapidly fool our immune systems by changing the proteins that line their surface. Every year, they put on a new disguise…
ddobbs | September 8, 2009From my wanderings. We'll start with the happy stuff
Salmon return to Paris! (photo: Charles Bremner, deep in Paris)
Mind Hacks tours some really old brains.
Zuska speaks wisely of health care reform.
The Guardian serves up some glass viruses (smallpox is pictured above).
Neuroskeptic covers a paper that is both encouraging, in its finding that EEG seems to predict antidepressant response, and infuriating, in that it withholds the information anyone else would need to replicate it. NOT GOOD.
The Wall Street Journal checks out cool tools to track the flu.
mikethemadbiologist | September 1, 2009During one of the many framing-related flare ups (kinda like zits, aren't they?), I argued that biologists have done the following things well while confronting creationism:
Calling creationists fucking morons (because they are).
Arguing that a better understanding of how life evolved is good in and of itself, and can imbue us with a certain sense of wonder.
Refuting specific creationist claims.
But this is what I thought was missing:
What we rarely do is make an affirmative, positive argument for evolution (as opposed to against creationism). I proposed one particular argument: we can't do…
edyong | August 25, 2009Since late 2006, honeybees in Europe and North America have been mysteriously disappearing. Once abuzz with activity, hives suddenly turned into honeycombed Marie Celestes. They still had plentiful supplies of honey, pollen and youngsters but the adult workers vanished with no traces of their bodies. The phenomenon has been dubbed colony collapse disorder (CCD). In the first winter when it struck, US hive populations crashed by 23% and in the next winter, they fell again by a further 36%.
Eager to avert the economic catastrophe that a bee-less world, scientists have been trying to find the…
edyong | August 23, 2009This article is reposted from the old Wordpress incarnation of Not Exactly Rocket Science. There's been more work on CCD since, but I'm reposting this mainly because of some interesting follow-up research that will I will post about tomorrow.
In 2006, American and European beekeepers started noticing a strange and worrying trend - their bees were disappearing. Their hives, usually abuzz with activity, were emptying. There were no traces of the workers or their corpses either in or around the ghost hives, which still contained larvae and plentiful stores of food. It seemed that entire…
edyong | August 21, 2009Viruses and bacteria often act as parasites, infecting a host, reproducing at its expense and causing disease and death. But not always - sometimes, their infections are positively beneficial and on rare occasions, they can actually defend their hosts from parasitism rather than playing the role themselves.
In the body of one species of aphid, a bacterium and a virus have formed a unlikely partnership to defend their host from a lethal wasp called Aphidius ervi. The wasp turns aphids into living larders for its larvae, laying eggs inside unfortunate animals that are eventually eaten from…
mikethemadbiologist | August 18, 2009...I was wrong. African-Americans and Latinos are already showing elevated numbers of swine flu hospitalizations in Massachusetts:
Since its arrival in Boston in late April, swine flu has proved to be a particular source of misery to the city's African-American and Hispanic residents, causing hospitalizations at far higher levels than other groups, disease trackers report.
More than 3 of every 4 Bostonians who have spent time in the hospital because of the viral ailment are black or Hispanic, a finding that may reflect broader social ills, the top official at the Boston Public Health…
edyong | August 12, 2009
When the bacteria that cause anthrax (Bacillus anthracis) aren't ravaging livestock or being used in acts of bioterrorism, they spend their lives as dormant spores. In these inert but hardy forms, the bacteria can weather tough environmental conditions while lying in wait for their next host. This is the standard explanation for what B.anthracis does between infections, and it's too simple by far. It turns out that the bacterium has a far more interesting secret life involving two unusual partners - viruses and earthworms.
A dying animal can release up to a billion bacterial cells in every…
edyong | August 10, 2009People infected with the bird flu virus - influenza A subtype H5N1 - go through the usual symptoms of fever, aching muscles and cough. The virus is so virulent that 60% of infected humans have died. But according to a study in mice, the infection could also take a more inconspicuous toll on the brain, causing the sorts of damage that could increase the risk of diseases like Parkinson's and Alzheimer's many years after the virus has been cleared.
The link between influenza and Parkinson's disease is hardly old but certainly controversial. Previous studies have found no traces of flu genetic…
mikethemadbiologist | August 3, 2009The CDC's expert committee has released its recommendations for who should receive the swine flu vaccination (TEH SWINEY FLOO!):
1. Pregnant women; household contacts and caretakers of children under 6 months old; health-care workers and emergency medical services workers; children and young adults ages 6 months through 24 years; adults ages 25 through 64 who have underlying medical conditions that put them at higher risk.
2. Healthy adults ages 25 through 64.
3. Healthy adults ages 65 and older.
This is a good list, but I have several concerns, stemming from the apparent lack of recognition…
edyong | July 9, 2009As the world is now painfully aware, pigs can act as reservoirs for viruses that have the potential to jump into humans, triggering mass epidemics. Influenza is one such virus, but a group of Texan scientists have found another example in domestic Philippine pigs, and its one that's simultaneously more and less worrying - ebola.
There are five species of ebolaviruses and among them, only one - the so-called Reston ebolavirus - doesn't cause disease in humans. By fortuitous coincidence, this is also the species that Roger Barrette and colleagues have found among Philippine pigs and even…
edyong | July 2, 2009The swine flu pandemic is well under way. With the WHO citing almost 60,000 laboratory-confirmed cases at the time of writing, the race is truly on to understand more about the virus. Now, two new studies have painted a fresh but partly contradictory picture about two of the virus's most important aspects - its infectivity (its ability to spread from host to host) and its virulence (its ability to cause disease in a host). These two traits will largely determine the threat that the virus poses, especially in relation to more familiar garden varieties of seasonal flu.
Both groups, one based…
edyong | June 29, 2009The swine flu pandemic (S-OIV) currently sweeping the world is the result of an influenza H1N1 virus that made the leap from pigs to humans. But this jump is just the latest leg of a journey that has taken over 90 years and shows no signs of finishing.
Today's pandemic is a fourth-generation descendant of the 1918 flu virus that infected around a third of the world's population. This original virus is an incredible survivor and one that has spawned a huge legacy of daughter viruses. By importing and exporting its genes, it has contributed to several new strains that have been responsible for…
edyong | June 11, 2009In the time since the words "swine flu" first dominated the headlines, a group of scientists from three continents have been working to understand the origins of the new virus and to chart its evolutionary course. Today, they have published their timely results just as the World Health Organisation finally moved to phase six in its six-tier system, confirming what most of us already suspected - the world is facing the first global flu pandemic of the 21st century.
The team, led by Gavin Smith at the University of Hong Kong, compared over 800 viral genomes representing a broad spectrum of…
mikethemadbiologist | June 10, 2009
I've been meaning to get to a really interesting article titled "Killing niche competitors by remote-control bacteriophage induction." So, let's talk about your nose.
Two species that are found in the human nose are Staphylococcus aureus (methicillin resistant strains are called MRSA) and Streptococcus pneumoniae. Typically, only one species or the other is found: they usually don't coexist in your schnozz. One mechanism that S. pneumoniae uses to displace S. aureus is to make hydrogen peroxide, but it's unclear how this actually works, since hydrogen peroxide, at concentrations which…
mikethemadbiologist | June 2, 2009A recent post about the looming specter of bioterrorism by William Lind due to 'biohacking' seems overblown to me. But before I get Lind, what I find particularly disturbing about hyping a non-existent bioterror threat is that it makes combating infectious disease--the stuff that kills millions worldwide--much harder due to unnecessary regulations and restrictions. Onto Lind:
For years, I have warned in these columns and elsewhere that the future weapon of mass destruction we should most fear is not a nuke. Rather, it is a genetically engineered plague, a plague no one has ever seen before…
bioephemera | May 29, 2009
Thank goodness Science has finally given us protection against. . . Kooties!
Kootie Killer promises to "kill 99.9% of germs & Kooties without water!" This claim is clearly rigorously lab-tested and evidence-based, but although I wouldn't dream of questioning its veracity, it does invite the question. . . what the heck is a Kootie?
Personally, I always thought cooties (with a "c") were symbiotic, invisible organisms that spontaneously accrued on children, causing healthy developmental conflict with members of the opposite sex. Shows you what I know. Apparently, the Kootie is a yellow-…
edyong | May 9, 2009
Immunity to viral infections sounds like a good thing, but it can come at a price. Millions of years ago, we evolved resistance to a virus that plagued other primates. Today, that virus is extinct, but our resistance to it may be making us more vulnerable to the present threat of HIV.
Many extinct viruses are not completely gone. Some members of a group called retroviruses insinuated themselves into our DNA and became a part of our genetic code. Indeed, a large proportion of the genomes of all primates consists of the embedded remnants of ancient viruses. Looking at these remnants is like…