Hi all,
This Tumblr is taking a brief nap - our chief Tumblr minion is off on holiday. It’ll start updating again on June 10th, and in the meantime you can always get your daily fill of biomedical beauty on our homepage, www.BPoD.mrc.ac.uk.
Until then, stay beautiful, BPoDers.
For decades, scientists around the world have studied cells growing in the lab as an alternative to using animals – a technique known as tissue culture. But some types of cells, such as nerves cells (neurons) deep in the brain, don’t grow happily in the unfamiliar and unrealistic environment of a plastic Petri dish. To get round this problem, researchers are developing complex techniques that ever more closely mimic the conditions of the cells’ original home. This tangle of fibres is a group of nerve cells from the hippocampus – part of the brain involved in memory – growing in the lab. Reassuringly, the cells are making plenty of connections between each other, as they would do in the brain, and can be kept alive for several months. This new approach will allow researchers to study some of the processes involved in memory and diseases such as Alzheimer’s more easily.
Written by Kat Arney
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To cure a disease you need to first understand its cause. Cancers come in all shapes and sizes, but genetic mutations – a few small changes in pivotal DNA sequences – play a role in almost every case. Acute myeloid leukaemia (AML) is an aggressive cancer of the blood that kills thousands of people worldwide each year. In a bid to understand what genes might be sparking the disease, scientists sequenced the genomes of over 200 AML patients, comparing the genetic sequences in their cancerous cells with those in their healthy cells. The result? A list of which genes and pathways contribute to the cancer. In this interactive graphic each dark line represents a single patient, connecting the mutations that appear in their cancer and revealing which mutations are most common. By identifying the genes that commonly cause the cancer, the researchers hope to dig up new ways to fight AML.
Written by Anthony Lewis
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(Source: bpod.mrc.ac.uk)
Stretch your skin and it springs back to shape – a property also possessed by the lining of your throat, inner ear, blood vessels and many other body parts. This springy tension is due to each surface cell having a tiny belt, formed by the proteins myosin and actin, wrapped around it, rather like an elastic band. Scientists have discovered that these belts are interlinked so that their stretching and squeezing actions spread like waves through the millions of cells, controlling the shape and movement of the surface (epithelial) tissue. Pictured (bottom) is a normal arrangement of surface cells of a rat’s intestine, with actin stained red and cell boundaries green. When myosin is chemically deactivated, the protein belts stop working, causing the cells to drift apart (top).
Written by Mick Warwicker
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(Source: bpod.mrc.ac.uk)
This is no ordinary printout. The pattern has been created not by ink, but by living human cells. Two types – stem cells (stained red) and blood vessel wall cells (stained green) – have been positioned on a patch using a device that’s similar to an office inkjet printer. Each cell type is released onto the patch in a set order, just as droplets of ink are printed onto paper. When the patch was applied to a damaged rat heart, the stem cells were able to help the blood vessels regenerate. Cells printed into a grid like this did a better job than those randomly jumbled up on the patch. Scientists now are beginning to print cells in three dimensions, creating made-to-order structures that resemble living tissues. Perhaps one day they will be able to print out whole organs at the touch of a button.
Written by Emma Stoye
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(Source: bpod.mrc.ac.uk)
Estimated to affect over 170 million people worldwide, diabetes is a major modern-day health concern. Caused by failure to regulate blood sugar, this disease arises because of defects in the production of insulin, a hormone that acts to decrease the levels of glucose in the blood, or in the way other tissues respond to it. Researchers have recently identified a hormone, named betatrophin, which is secreted by liver and fat tissue, and stimulates duplication of insulin-producing cells in the pancreas. Raising the levels of betatrophin makes the pancreatic cells replicate faster, and having more of these cells means that more insulin is made. In the mouse pancreas pictured, the pink spots identify a protein characteristic of replication, thus revealing that some of the cells that produce insulin (stained green) are duplicating. Also found in humans, betatrophin could provide potential alternatives to insulin injections in the treatment of diabetes.
Written by Emmanuelle Briolat
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(Source: bpod.mrc.ac.uk)
Form follows function. The way something works is intrinsically linked to the shape it takes. Haemoglobin – the molecular messenger bags used by red blood cells to courier oxygen around the body – is no exception. Max Perutz – born on this day in 1914 – developed a technique to reveal haemoglobin’s structure, and in the process became a founding figure of the emerging field of molecular biology. The X-ray crystallography techniques of the early 1950s, based on firing X-rays at a molecule and observing how they reflect off, couldn’t handle a molecule as complex as haemoglobin. But by adding a heavy metal atom to the protein Perutz solved the problem: the resulting change in X-ray behaviour could be interpreted to explain the molecule’s 3D structure. This revelation on how to determine the structure of proteins won him a share of the Nobel Prize for Chemistry in 1962.
Written by Anthony Lewis
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(Source: bpod.mrc.ac.uk)
This bull’s sperm may hold the key to choosing the sex of our future babies. Its head – roughly 10,000 times smaller than a cotton bud – contains an X chromosome, with genes destined to produce female offspring. The sperm’s surface has been mapped out in 3D using atomic force microscopy, which traces minute bends and dips to reveal hidden details. Comparing groups of features like ‘roughness’, ‘roundness’ and ‘circularity’, it’s possible to tell ‘female’ sperm from ‘male’ ones (containing a Y chromosome). This new method might one day improve ‘sex sorting’ in humans, where sperm can be selected to avoid hereditary, sex-specific diseases. Using sex sorting simply to allow a couple to predict or choose their baby’s sex is controversial, yet as potential boys and potential girls become easier to spot under a microscope it raises an interesting question – if you could choose, would you?
Written by John Ankers
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These glistening dew-like droplets are a death trap for insects, but could be a symbol of hope for surgery patients. The sundew (Drosera sp.) is an insectivorous plant that entices and then snares its prey with tentacles covered in gluey mucilage. Taking inspiration from nature, researchers believe this natural adhesive might have many medical uses. A complex network of carbohydrate-based nanofibres, sundew’s secretions are super-sticky and extremely stretchy. The most valuable property of this biomaterial is that animal cells can attach to and grow on it. If surgical implants, like hip replacements, were coated in sundew adhesive they might be more quickly integrated into the body, reducing rejection and improving recovery rates. It could even be used for wound dressings – promoting faster healing by encouraging cell growth. As the mucilage is so stretchy a little goes a long way, making it cost effective too.
Written by Sarah McLusky
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Tobacco may soon shed its negative image by becoming a pharmaceutical factory. The disorganised blobs of tissue pictured, known as callus, will grow into genetically modified tobacco plants that can produce a therapeutic anti-HIV antibody. Molecular farming (also known as ‘pharming’) involves genetically modifying plants to produce medically useful proteins like antibodies, vaccines and hormones. Tobacco is ideal for pharming as it’s easy to grow and harvest, and as a non-food plant, there’s no chance of gene transfer into the food chain. The first small-scale clinical trials of the tobacco HIV antibody have shown it’s safe, and further testing will establish if it’s effective. ‘Plantibodies’ could revolutionise medical treatment, reducing costs dramatically, but concerns over the safety and ethics of large-scale production have slowed progress. If these trials are successful, perhaps greenhouses will become the drugs factories of the future.
Written by Sarah McLusky
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