HIV escaping from a white blood cell
Researchers have for the first time unravelled the complex structure of the inner protein shell of HIV.
The US team, reporting in Nature, also worked out exactly how all the components of the shell or ‘capsid’ fit together at the atomic level.
Until now the exact structure had proved elusive because of the capsid’s large size and irregular shape.
The finding opens the way for new types of drugs, the researchers from the University of Pittsburgh said. It was already known that the capsid, which sits inside the outer membrane of the virus, was a cone-shaped shell made up of protein sub-units in a lattice formation.
Image via AHA
Cardiovascular disease experts are increasingly interested in two biomarkers, NT-proBNP and troponin T, whose presence in blood has been repeatedly and consistently correlated with heightened risk for heart attack and, according to a new study by doctors at my hospital, stroke, silent stroke, and ischemia-caused brain disease.
Researchers are growing confident enough about these biomarkers that some are calling for them to be measured fairly early on in life, as part of a battery of tests meant to assess a patient’s risk.
Work to clear up the correlation also continues. There’s already lots of evidence that NT-proBNP and troponin T production aren’t accidental correlatives, but are indicators of various metabolic and physiological processes that will, over time, directly affect cardiovascular health.
Today’s Google doodle is composed of interactive petri dishes in celebration of Julius Petri’s 161st birthday!
To me, there’s something really funny about the fact that a guy took a round dish with a lid, literally the most obvious and utilitarian thing you could think of to grow bacteria in, and named it after himself (or we named it after him, perhaps).
Imagine if a cup were called a “Smith vessel” or if a paper bag were called a “Wilson sack”. “Hey! Can I have a Smith vessel of coffee?”
But on the other hand, science is regularly a business of serendipity, scratching away to reveal the layer just beyond the obvious, and being ready in the starting blocks to run when luck drops something in your lap.
Just be sure to name it after yourself when that happens.
Triage is one of the most important words in medicine, and its origins are complex and interesting.
The word was originally used in the early 18th century by the French and, later, English, to describe the sorting of things, such as yarns or cooking ingredients. It was a new noun, derived from the French verb trier, “to sort.” At this point triage was not used in medicine, or whatever form of butchery/quackery they were doing back then.
The first person known to use triage in a distinctly medical way was Dominique Jean Larrey, who used the term to describe the way in which wounded soldiers of the Napoleonic Wars would be prioritized according to their injuries. From a translated medical paper:
Those who are dangerously wounded should receive the first attention, without regard to rank or distinction. They who are injured in a less degree may wait until their brethren-in-arms, who are badly mutilated, have been operated and dressed, otherwise the latter would not survive many hours; rarely until the succeeding day. Besides with a slight wound, it is easy to repair to the hospital of the first or second line, especially for the officers who generally have means of transportation. Finally, life is not endangered by such wounds.
But triage did not become a commonly used term until World War I, when French doctors began prioritizing the wounded into three groups:
- Those who are likely to live, regardless of what care they receive;
- Those who are likely to die, regardless of what care they receive;
- Those for whom immediate care might make a positive difference in outcome.
It is not clear whether the doctors intended for there to be three groups because of the Latinate suffix of triage (tri-, or three), or whether that is mere coincidence. As triage's original meaning had nothing to do with three, this may be a case of a word's shape and form nudging us toward new meaning.
Forever alone level: PhD.
Foot fungi a thriving, diverse community
More than 80 different types of fungi make human feet home, researchers report May 22 in Nature. The tiny organisms stake claims all over a person’s skin, but only the feet carry such a diverse group of settlers, says study coauthor Julie Segre, a geneticist at the National Human Genome Research Institute in Bethesda, Md.
The study is the first census of skin-dwelling fungi. By helping to identify differences between healthy and unhealthy fungi, it could one day lead to targeted treatments for athlete’s foot or toenail infections.
— Meghan Rosen, Science News
Reo Kometani and Shinji Matsui
A new study of epithelial mucus in a wide variety of animals shows bacteriophages — viruses that attack bacteria — are far more prevalent (relative to their bacterial prey) when there’s more mucus around.
The authors from San Diego State, UC San Diego, and Rainbow Rock (whatever that is) suggest mucus membranes may have evolved, in part, to provide a friendly incubator for bacteria-killing viruses.
If they’re right, that means there’s a new dynamic to consider when pondering the thickness of mucus membranes. Too much mucus can impede the exchange of oxygen, or the absorption of nutrients. Too little mucus could mean an ulcer, or now, we learn, too little space for helpful viruses to live in.
Rebloggable by request.
As unsatisfying as this may be, the answer is actually “we don’t know.”
Noting that non-human animals behave differently and even predictably under stress, or that physiological changes apparently caused by social starvation are not enough to conclude non-human animals experience “mental illness” — that is a human-defined concept, defined by human experiences and human behavior. The risk of anthropomorphizing non-human animal behaviors here is great, particularly when the comparisons we draw between humans and other animals are made coarsely, e.g. concluding other animals experience mental illness because their brains overproduce the same neurotransmitter receptors we see overproduced in, say, clinically depressed (human) patients.
Not only is human psychology tricky in that it is “somewhat subjective based off of interpretations by the patient,” but psychology itself can be subjective, for example, its categorization of mental illnesses, which seem to change every decade or so.
Any organism that has a brain can have a brain that works poorly, or that initiates behaviors that are unhelpful to the organism’s health, survival, and reproduction. But science has not yet shown us is whether (a) there is a proper distinction to be made between a brain that is broken and a brain that is ill, and (b) the experience of mental illness in non-human animals, if it exists, is equivalent on some level to the experience of mental illness in humans.
I think psychologists are doing the best they can, given dogs can’t tell the researchers how they’re feeling (or how the dogs are feeling, for that matter), but the fact is, the field is not far enough along to be answering big questions like this. Hard work and patience are yet required.
Bill Murray sniffing a Baby Ruth in Caddyshack
Nancy Shute, writing for NPR.org:
Everybody In The Pool! But Please Leave The Poop Behind
Perhaps you’ve noticed a toddler’s sagging swim diaper and wondered if it’s really keeping the poop out of your neighborhood pool.
The Centers for Disease Control and Prevention has the answer for you: no.
Last summer, researchers at the federal public health agency collected 161 filter samples from public swimming pools in the Atlanta area. More than half of those samples, 58 percent, were contaminated with E. coli.