Blood Battles

A bacteria is sauntering around an organism, ready to attack and wreak havoc, but what's that? A chemical comes and traps the bacteria in this big sticky-like goo. Now what I described was not something in a sci-fi novel, but actually something that scientists do today and it comes from an unlikely source, the horseshoe crab Limulus polyphemus. This crab which if encountered by a human in a shoreline would be probably ignored, has special blood that makes it a supreme bacteria killer.

In an article from The Atlantic, it talks about the medicinal benefits of extracting the blood from the horseshoe crabs. How it works is that a particular chemical called coagulogen is contained in the amoebocytes of the crabs blood cells. This chemical can detect traces of bacteria and then trap it in something that scientist Fred Bang coined as a “gel”. How scientists use it is effectively in the same vein, they take the coagulogen chemical and put it in a solution containing bacteria. If it did not have bacteria then no gel substance would be formed and one would know the solution contained no bacteria. This test, which is called Limulus amebocyte lysate test, or LAL for short is actually used for detecting contaminated substances. The PBS documentary Nature actually said “Every drug certified by the FDA must be tested using LAL, as do surgical implants such as pacemakers and prosthetic devices.”

Yet, with anything in this world, there are drawbacks. Millions of horseshoe crabs must be used to get tons of their blood. The horseshoe crabs don’t die though, but the blood draining has long term effects. A research done and published in The Biological Bulletin points out that female horseshoe crabs that have been bled are lethargic and slow and less likely return to the shoreline where they were found. This is significant because females mate near the shoreline but now do not possess the vitality to make the trip and this reduces chances to mate.

Biomedical research is accelerating at a blistering pace, as shown by the miracle which is the blood of horseshoe crabs. While benefitting the human race, we must also understand the effects it has on the species we use, making this not just a biomedical issue, but an ecological one as well.

Posted by Jacob Geier (5-B)

Design Behind Flight May have Arose Earlier Than Previously Thought

The evolution of flight has baffled scientists for ages. Many theories have arisen in attempts to explain this marvelous phenomenon, but a new study suggests the evolutionary process may have begun much earlier than previously depicted. The common notion in circulation is the adaptive feather theory. This theory suggests that feathers became present as a by-product of evolution; rising from a mutation in set of genes that also code for hair and scales in other species. These genes, known as box-set-genes, have been mainly unaltered for millions of years. However, mutations have arisen over time, and as a result, feathers became available to early dinosaur-bird-like species. The bird evolutionary branch has two major extant divisions that biologists agree on. These are the ratites (flightless birds) and the neornithes (modern birds). The idea behind the rise of feathers is that they gave early bird species some benefit in either running faster, escaping prey, or attracting a mate. Which mechanism is unknown, possibly all of them, but fossil evidence suggests the presence of an ancient bird-like creature that had feathers not capable of flight. And so the adaptive flight theory is born.

A new study looking at elements preceding the evolution of flight, such as, arm length and body size, among earlier species of birds, suggest this process began much earlier than previously mentioned. A 2014 articles states, “Being small and light is important for a flyer, and it now seems a whole group of dozens of little dinosaurs were lightweight and had wings of one sort or another. Most were gliders or parachutists, spreading their feathered wings, but not flapping them”. This is an interesting idea and supports the adaptive feather theory. Often, evolution takes many steps, twists, and turns to produce an observable outcome. It's known that mutations in the genes coding for hair and scales gave rise to feathers, and adaptions in the morphology and functionality of arm length/ body size both are a major influence in the rise of flight. Researcher Mark Puttick stated, "We were really surprised to discover that the key size shifts happened at the same time, at the origin of Paraves," said Mr Puttick of Bristol's School of Earth Sciences. "This was at least 20 million years before the first bird, the famous Archaeopteryx, and it shows that flight in birds arose through several evolutionary steps."

Evolution is never as clear cut as it seems on paper. New fossil evidence, new studies, and predictions made based on previous studies/fossils help give insight into how life evolves. It is an ever-changing science that is subject to the latest research and discovery to guide us further. This newest development supports and complements previous theories regarding flight, as well as, provides new insight in an area previously not so well understood. It takes scientist challenging and comparing every aspect of nature, genetics, and development among species to get a clear cut picture of the evolution occurring. This newest studying is guiding us in the right direction of one day fully understanding the mysteries behind flight.  

posted by Maxwell Liner (5)

Silk-Based Implants, a Shift from Metal

Scientists in the United States have undertook the process of trying to replace the metal fixtures; screws, rods, and plates that patients have implanted into their body in the cases of fractured or broken bones. The replacement is made from a natural fiber, silk,  an exceptionally strong and versatile protein derived from silkworm cocoons. Leading this research is Samuel Lin, MD, of Division of Plastic and Reconstructive Surgery at BIDMC, and David Kaplan, Tufts chair of biomedical engineering and a leader in the use of silk for biomedical applications. Kaplan and his team have already developed silk based sponges and foams for operation rooms.

Silk has already been used in modern medicine for other implants, one in the Journal of Clinical Investigation, published in July of last year researched the possibility of silk brain implants helping those suffering from epilepsy. Metal implants over time can cause stress to underlying bone, cause stiffness, and can also lead to increased risk of infection. The silk would eventually dissolve in the body, seeing as the composition of the protein is similar to that of bone. What is important to note in the study regarding the replacement of metal plates with silk, is that in the silk implants are successful, it would eliminate the need for surgical removal of the devices, those which can be removed. Also, the silk based screws can deliver antibiotics to help prevent infections from poor healing wounds and promote bone regrowth.

The test so far has only been done on rodents, six laboratory rats, which had a total of 28 silk-based screws implanted into their hind limbs, and then monitored  for eight weeks. Through those eight weeks, the screws kept their mechanical integrity, and showed signs of dissolving after those eight weeks. Post-implantation, silk-based screws are extremely advantageous to clinicians due to silk's radiolucent property, they won't show up on an X-ray, allowing for a more accurate assessment of the healing process. This application was originally treatment for facial injuries, which occur at a rate of several hundred thousands each year, but could potentially help millions of people and improve their quality of life.

Posted By Thomas Flores (5)

Using Stem Cells Derived from Adipose Tissue to Regenerate Cartilaginous Tissue

Most of us take for granted what we look like, how our bodies work, and at the same time assume that things will be the same tomorrow. Unfortunately for numerous patients suffering from diseases such as microtia this isn’t the case.  Either born with abnormalities to their cartilaginous tissue, or from a debilitating disease there are many people who suffer from damage to their nose, ears, or other cartilage based organ. This poses many problems for those afflicted, from loss of function to social and mental distress. Some cancer surgeries also result in a loss of, or damage to facial cartilaginous structures. This can be incredibly demoralizing for someone who is fighting for his or her life. Fortunately with new scientific discoveries it doesn’t need to be this way forever.

A recent article in BBC news describes a new technique by which doctors are able to take adipose tissue from a patient, and then using chondrogenic differentiation transform the fat cell into a stem cell. From there they can regrow the cartilaginous tissue using a nano-sized scaffold to guide its growth. The eventual result is a cartilage structure of a predetermined size and shape. This structure can then be surgically implanted into the patient. The ultimate goal of this procedure would be to encourage the structure to continue to grow so that it matches pace with the host body and ensures that no more surgeries are needed.

While similar cartilage structure creations do exist already they are typically harvested from a source on the body (eg. the ribcage) and then sculpted to look like the appropriate organ before being surgically implanted. At which point the structure does not continue to grow, requiring the patient to undergo multiple surgeries simply to keep a functioning and similarly sized organ. Furthermore each successive surgery requires a new structure, so more cartilage needs to be removed from the ribs – where it does not grow back – before it can once again be sculpted into the required shape.

While this use of adipose-derived stem cell is limited to a fairly specific niche it nonetheless paves the way for future advances of this technique. At this point researches have shown that it is possible and have succeeded in growing a cartilage scaffold, however before they can begin implanting them into human subjects they need to first verify that the procedure is truly as safe as it sounds. One of the benefits of using adipose derived stem cells is the negligible risk of rejection from the host body, as the stem cells originated from the same person. This combined with numerous successes using stem cells from other sources (eg. bone marrow) have scientists feeling optimistic about this new procedure.

Posted by Kirk MacKinnon (5)

Would You Pick Protein or Carbohydrates?

Many college students have been going to gym and workout throughout school year. And most of them know that to get a fitter body, “low-carbs, and high-proteins” diet should be incorporated with their workout. It is obvious for the body builders to know that carbohydrates will breakdown into smaller sugar forms. So they would prefer diets with lower-carbs in general. It helps them to reduce the amount of sugar transforming into fat. And yes, it makes perfect sense that taking in plenty of protein allows body to rebuild stronger muscles faster after workout. Yet, for long-term speaking, should we consume as much protein as possible the better?

According to Francine Segan, a food historian, many ancient writers wrote that Olympic athletes would avoid grains and breads for half a year. She also said there are many fragments of other documents suggest that athletes consumed diets rich in protein and fibers—also as known as Mediterranean diet. Even ancient athletes believed in high protein and low carbohydrates diets help to build stronger, more enduring muscles. The fact that high lean protein diets help us build muscles with better performance is supported by many scientific researches.

Another research group led by Stephen Simpson andDavid Le Couteur at the University of Sydney conducted an experiment which assigning different diets to mice and compare their average lifespan. For the result, the low-protein/high-carbohydrate diet appears to extend lifespan. The study shows that animals with this diet had lower blood pressure, better glucose tolerance, and healthier cholesterol. Those mice consumed lots of protein were skinner but lived shorter than the otherwise. But how come fatter animals are healthier? There are findings state that reducing protein intake can lower the level of IGF-1 growth factor, which with higher level has a greater risk of cancer and diabetes. Low level of protein can also lower the level of mTOR, which with a lower level can extend the lifespan of mice.

These studies suggest that high level of protein is able to create the leanest muscles with better performance. However, it could also shorten the lifespan of animals. If high level of protein consumption will lead to shorter lifespan, is most of the body builders and athletes achieving health and longevity or the otherwise?

Posted by Yim Hui

The Dire Wolf Extinction Mystery

If anyone is a Game of Thrones fan, you have probably heard of the dire wolf. In the Game of Thrones series, dire wolf pups were found, taken in, and raised by children. They grew very large, like a present day oversized gray wolf with heavier build and were fiercely loyal, protecting each of the children that raised them.

The dire wolf, unlike some of the fictional creatures in the series, actually lived up until about 10,000 years ago before going extinct. The dire wolf was big, weighing up to 175 pounds fully grown making it the largest in the Canis species. It was similar to the gray wolf but with much larger jaws and teeth and a heavier build. The dire wolf’s legs were shorter and it had larger pelvic bones and shoulder blades. The wolf was a carnivorous mammal, mostly found in North and South America, with the most fossils (upwards of 3,600) being found in the Rancho La Brea tar pits in California. The amount of gray wolf remains found in the pits was only 1% of that of the dire wolf. It is believed the dire wolf used the animals that were caught in the tar pits as a food source and consequently also became stuck. Such a large number of remains suggested that the wolves were pack hunters.

If the dire wolf was bigger and more powerful than the gray wolf, why did it go extinct? The answer to this question is not certain and there are a number of theories. The most prevalent theory suggests that the dire wolf’s adaptation for power over speed actually contributed to its demise. The wolf preyed on a number of fairly inactive large herbivore species, so when they became extinct the wolf was not able to catch other faster prey that remained. It is also theorized that the extinction of the dire wolf coinciding with prevalence of humans in North America could be related to an increase in hunting these large wolves or that both the humans and wolves were competing for the same food source.  More research and information will be needed in order to concretely determine what the main factor leading to their extinction was.

As an interesting side note, there is a group of dog breeders attempting to bring back the size and look of the dire wolf, crossing German Sherpards with Alaskan Malamutes as the base breed. The project began in 1988 and the breed is still progressing.  

Posted by: Morgan Matuszko (5)

Neurogensis in the Adult Brain May be More Important Than Previously Thought

When it comes to brain development the common wisdom used be that once you’re an adult you won’t be generating any new neurons so, be careful with the ones you have. Research has since contradicted that, showing new growth of neurons in at least the hippocampus. Growth of new neurons in the hippocampus does make some sense, as it seems to be the area of the brain devoted to memory. Scientists wanted to figure out if any other parts of the brain can generate new neurons. Recent research published in Cell shows where many of these new neurons are being developed and their potential for migration.

Results were obtained by measuring the amount of C14 present in the genetic material of neuronal cells. Since atmospheric C14 levels changed over time, finding those differences in neurons means that new neurons have been generated. The lateral ventricle and hippocampus is where most of these neurons are created. Those created in the lateral ventricle are interneurons, migrating to the adjacent striatum. When the brain isn’t creating these neurons normally the brain becomes diseased.

           The research done shows that patients with Huntington’s disease have decreased or completely absent neuronal regeneration in the striatum. Huntington’s disease is characterized by neurodegeneration and decrease in cognitive ability. This correlation may be an important part of finding the true cause of the disease, and a treatment. Thinking about the generation of new neurons has gone from an unacceptable idea to what may be an integral part of the healthy human brain.


http://www.sciencedirect.com/science/article/pii/S0092867414001378




-Stephen O'Brien