BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: Disease (Page 2 of 2)

Save the Devils

When most people hear the name Tasmanian Devil, they think of the small and ferocious little animal from the Looney Tunes named Taz. Just like in the show, Tasmanian Devils (carniverous marsupials)  are tough, rugged and very aggressive animals. Unfortunately, over the past two decades, a rare case of contagious facial cancer, with a 100% mortality rate, has decimated the population. Scientists have estimated that this specific cancer has wiped out about 85% of the entire population, almost to the point of extinction. The cancer is typically spread when the Devils bite each other in the face during battle, killing it in a matter of months. Scientists are working tirelessly to find out how this cancer is slipping by the immune system and hope to find a cure.

Until recently, scientists believed that the cancer was able to develop, without

being detected by the immune system, because Tasmanian Devils lack genetic diversity. However, a study led by the University of Cambridge claims it is much more complex. On the surface of most cells are histocompatability complex (MCH) molecules, which determine whether other cells are good or bad. If the cell happens to be a threat, then the cell triggers an immune response. According to the research, these DFTD cancer cells lack theses complexes and can therefor avoid detection.

Researchers also found that the DFTD cells have just lost the expression of MCH molecules and that its genetic code is still in tact (it can be turned on). By introducing specific signaling molecules, scientists believe they can force the DFTD cells to express these molecules, leading to the detection of the cancer. Not only will this research help save the Devils, but it will also give scientists a head start on contagious cancers in other species when the time comes.

Trial for New ALS Treatment Failed

Photo by: Nemo

Biogen Idec, a drug developing company, has recently discontinued their work on a new drug that was, hopefully, going to help patients with Amyotrophic lateral sclerosis, also known as ALS or Lou Gehrig’s disease. A recent article explained that a new drug, known as dexpramipexole, was not effective in the phase 3 trial of the study.

Amyotrophic lateral sclerosis (ALS) is a disease where nerve cells “waste away and die.” These cells are unable to send messages to muscles, therefore symptoms include paralysis and muscle weakness. The progression of the disease is slow and “once the patient loses the function of muscles in the chest area, it becomes hard to breathe.” There is no known cure for this disease but scientists are looking for ways to prolong the disease.

Biogen Idec believed that the drug, dexpramipexole, was hopefully going to “slow the progression of loss of muscle function and prolong the lives of people with the disease.” While the phase 3 trial was not successful, the phase 2 trial of patients receiving dexpramipexole showed some success. 50% of the patients, in the second trial, showed a slower decline of muscular function. This was a big accomplishment for Biogen Idec but the phase 3 was not as effective. Therefore, Biogen Idec’s study involving a new treatment for ALS ended.

Even though Biogen Idec’s study was not effective, other companies have successfully found a way to slow the progression of ALS. Thus far, only one drug has been approved to help patients with ALS. This drug is known as Rilutek/Riluzole and it is only modestly effective.

Doctors are in need of a new drug that will help patients with ALS. I think its great that companies like Biogen Idec are involved in finding a way to treat this rare disease. I hope that researchers will use the information from the failed trial to find another way to treat ALS.

Genome Project Helps Connect Ethnicity to Diseases

Though people from all over the globe share over 99% of the same DNA, there are subtle differences that make us all individuals

Scientists at the Washington University School of Medicine in St. Louis have started the “1,000 Genomes Project” in which they will decode the genomes of 1,000 people from all over the world in hopes of finding genetic roots of both rare and common diseases worldwide. On October 31st, the results of DNA variations on people from 14 different ethnic groups were published, but the scientists hope for the project to expand to involve 2,500 people from 26 different world populations. According to Doctor Elaine Mardis, co-director of the Genome Institution at Washington University, “[scientists] estimate that each person carries up to several hundred rare DNA variants that could potentially contribute to disease. Now, scientists can investigate how detrimental particular rare variants are in different ethnic groups.”

 

We are One

Everyone on earth share 99% of the same DNA. That means you, your best friend, your mortal enemy, your boyfriend/girlfriend, next door neighbor, and The President of the United States all share 99% of your DNA. However, there are rare variants that occur with a frequency of less than 1% in a population that are thought to contribute to both rare diseases and common conditions (i.e cancer, diabetes). The rare variants explain why some medications do not effect certain people or cause nasty side effects (i.e insomnia, vomiting, and even death).

 

The goal of the “1,000 Genomes Project” is to identify rare variants across different populations. In the pilot phase of the program, researchers found that most rare variants different from one population to another, and the current study supports this theory.

 

The Study

Researches tested genomes from populations from the Han Chinese in Beijing (and the Southern Han Chinese in China) to Utah Residents with ancestry from Europe to the Toscani people of Italy to the Colombians in Columbia. Participants submitted an anonymous DNA sample and agreed to have their genetic material on an online database. Researchers than sequenced the entire genome of each individual in the study five times. However, decoding the entire genome only detects common DNA changes. In order to find the rare variants, researchers sequences small portions of the genomes about 80 times to look for single letter changes in the DNA called Single Nucleotide Polymorphisms, or SNPs.

 

The Results and Importance

The Study concluded that rare variants vary from one population to another. Researchers found a total of 38 million SNPs, including 99% of the rare variants in the participants’ DNA. In addition, researchers found 1.4 million small sections of insertions or deletions and 14,000 large sections of DNA deletion. The “1,000 Genomes Project” is incredibly important in medical science. It now allows researchers to study diseases, such as cancer, in specific ethnic groups. I personally think this project in incredibly important. As an Ashkenazi Jew from Eastern Europe, my family has a medical history of certain cancers and diseases. With the results of the “1,000 Genome Project,” researches could potentially find out why, and maybe even find a cure for some of these diseases.

Wait, you don’t hear that ringing, too?

Defined as “the perception of sound in one or both ears or in the head when no external sound is present” by the American Tinnitus Foundation, tinnitus affects 50 million people in the US and forty percent of veterans.  It can be caused by everything physical trauma or long-term exposure to loud noises (i.e. combat veterans or teenagers with iPods) to hormonal imbalance or aspirin use. Currently, there are many treatments available, although the success rate of these treatments varies. The main reason for this is that the best way of treating tinnitus would involve delivering medication to the inner ear, the site of the problem. Currently, doctors have no way of putting medication in the inner ear, but this could change  in a few years thanks to the the beginning of a new project by the US Department of Defense, who has commissioned Draper Laboratory to work out a

concept for a small delivery device inserted near the membrane-covered window—no more than three millimeters in diameter—separating the middle ear from inner ear. Once at the membrane the device … would release a drug into the cochlea… The plan is to embed wireless communications into the capsule so that a patient or doctor can control the dosage. After the capsule finishes delivering its supply of drugs, it would dissolve. 

 

Courtesy of: http://www.lesliewong.us/blog/2009/01/23/sony-mdr-v6-and-sennheiser-cx300-headphones/
These may be setting up my generation for a tinnitus epidemic many years from now.

 

The project is only in its beginning stages, so it will be years before patients can actually reap any benefits from this technology. However, I take comfort in knowing that should I develop tinnitus, I could possibly have access to better treatment than is available today. This is especially relevant to my generation; everywhere you look, there are teenagers blasting their iPods, unknowingly (or not caring) causing permanent damage. Despite the warnings received from adult, many teens will not listen, and will continue to cause damage with loud noise. Should this treatment be developed, the tinnitus that will be inevitable developed by a large portion of my generation will treated, and possibly cured.

This project also holds a personal significance for me.  As someone who wants to eventually enter the armed forces, I am relieved to know that such a common issue among veterans is coming a step closer to being eradicated. Despite the technology used today to prevent noise damage,  I know of Iraq and Afghanistan war veterans who are experiencing tinnitus, and even hearing loss. I’m glad that research is being conducted on a condition that, while it may not sound terribly crippling, can actually have a huge effect on one’s quality of life.

So, readers, do any of you have or know someone with tinnitus  If so, how did you or the person you know develop it? And, if you have it, would you consider one day utilizing this kind of treatment?

Post, discuss, talk with your friends. Discussion breeds awareness, which is key to arriving at a cure. 

 

 

http://www.scientificamerican.com/article.cfm?id=tinnitus-treatment

New Deadly Virus Discoved in Africa

Recently an article was released summarizing the discovery of a new disease in Africa. In 2009 a fifteen year old boy in a small village in the Democratic Republic of the Congo fell ill. The initial symptoms were malaise and a bloody nose, but quickly the boy developed an acute hemorrhagic fever. Within two days of the showing symptoms the boy died. Approximately eleven days later a thirteen year old girl who went to the same school as Patient One developed similar symptoms, and died three days later. At the local health center which both Patients One and Two visited, a thirty-two year old male nurse began to experience identical symptoms. He was moved to the hospital in Boma, Democratic Republic of the Congo, where the doctors drew blood and began to test for known viruses; they found nothing. However, very recently a research team used deep sequencing to determine the pathogen,which they dubbed “Bas-Congo Virus”, and posted their results in the Public Library of Science Journal. It was discovered that the virus belonged to the Rhabdoviridae family, best known for the Rabies virus. Interestingly enough, though, the Bas-Congo virus only shares 34% of the amino acids found in other Rhabdoviruses, meaning that it is very different. The discovery of this virus may end up being of great importance due to the possibility that the virus may return. In any case, we will have one less pathogen on this planet to identity lest there be another, more deadly, outbreak.

Vitamin D is linked to depression, so start sunbathing!

Haven’t been in the sun too much this winter season and feeling depressed? Well, it may be due to the fact that low levels of vitamin D are now linked to depression. According to a recent article, low vitamin D levels are already linked to cardiovascular diseases and various neurological problems. However, a new study links the connection between low vitamin D levels and depression. At the UT Southwestern Medical Center, researchers examined 12,600 subjects from 2006 to 2012. Results showed that subjects with higher vitamin D levels, who had a previous history of depression, had a larger decreased risk of depression at the time. Participants with low levels of vitamin D were shown to have signs of depression. Although the study the relationship of vitamin D and depression, the study did not show if increasing vitamin D in your diet actually reduced those depressive-like symptoms. Also, scientists have not confirmed whether or not low vitamin D causes depression like symptoms or if depression is causing low vitamin D levels. One could say low vitamin D levels are linked to depression however, adding vitamin D to your diet would not necessarily cure depression-like symptoms.

Many concepts around the idea of vitamin D being linked to depression are still unknown, but I think it is still a very important topic to discuss and important further research the subject.  The psychiatrists the UT Southwestern Medical Center have reported that major depressive disorder affects one in ten adults in the United States. One-tenth of our adult population has depression. When you put it into perspective, that is one person in a room of ten people. If that is the case,  then for me this is a field where the link between vitamin D and depression needs to be further researched. For now, it won’t hurt some sunshine to get your daily dosage of vitamin D.

 

Human Health in the Hands of a Naked Mole Rat?

Our genome is similar to that?!

         What do you think of when you see a naked mole rat? Do you think it is hideous because it has no fur? Do you think you would want to pet it? Whatever you think about this animal, you would never expect that it could improve human health. Who knew they could be the key to increase the human life span? Yep, that’s right! Naked mole rats, as ugly as they may be, are now considered extremely helpful and important in designing treatments for fatal diseases.

            A recent study discovered that the newly deciphered genome of the naked mole rat could help researchers learn more about evolution and even help design better treatments for diseases like cancer and stroke. Scientists believe that this genome will help decipher the naked mole rat’s unique traits, behaviors and social characteristics.

            Scientists who deciphered the naked mole rat’s genome used shotgun sequencing to read it. The naked mole rat was raised in a lab and once it was an adult, the scientists studied its genome. They read long sequences of the nucleobases that make up the rat’s DNA and then lined them up to find where they overlapped. Once they read the complete genome, the researchers compared it to the genomes of humans and mice.

            The researchers found multiple mutations in the naked mole rat’s genes that correlate to its characteristics. They found that the rat had turned off several genes related to vision because they live in the dark. They also saw a mutation in the gene that functions in hairlessness, which explains why these rats are bald. Naked mole rats live in low-oxygen burrows and stroke and heart attack deprive parts of the body from oxygen. By comparing the genome of the naked mole rat to the human genome and discovering how they survive in this type of low-oxygen environment, scientists can design more effective treatments to improve diseases that deprive the body of oxygen. The researchers sequenced the whole genome and will make it available free online, so groups that study genes involved in cancer and longevity can compare those genes to the mole rat’s genome. You can even look it up online and determine for yourself which genes you think are similar to ours!

            This new information about the naked mole rat’s genome can be extremely helpful for treatments that could increase the human life span and improve human health. Who knows, maybe the deciphering of the genome could even lead to find the fountain of youth! What do you think? Do you think the rat’s genome is similar enough to ours that scientists can design more effective medication for diseases? How far do you think these researchers are able to go? If you are unsure, just be sure of one thing, the next time you see a naked mole rat, be sure you look at it with a different perspective because in twenty years that very rat’s genome may lead to the cure for cancer!

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