Penne's Bio-heat model... not sufficient, or is it...

One method of treating tumors is by use of hyperthermia. In order to implement this treatment a sufficient understanding of the attendant thermal processes in diseased and normal tissue must be attained. It is vital to be able to predict, measure, and interpret the tissues thermal and vascular response to heating appropriately if one is going to use such a treatment. The problem lay herein, living tissue morphology is of a complex nature, and thus modeling of its properties can be quite difficult. In studies past, researchers have used some simplifying assumptions that would presume to be needed. However, there have been investigators recently who have argued that “Penne’s interpretation of the vascular contribution to heat transfer in prefused tissues fails to account for the actual thermal equilibration process between the flowing blood and the surrounding tissue and proposed new models, presumably based on a more realistic anatomy of the perfused tissue” (Holmes,K.R, Arkin, H. Xu, L.X.).
This article gives an analytic comparison of several new bio-heat transfer models and places specific focus on the problems “of their experimental validation.” Since there is very little measuring equipment able to map out the tissues properties with all its variations at the spatial scale of blood vessels (i.e. diameters of less than .2 mm), the new models lack experimental support and thus are subject to error. All and all, the best way to map this bio-heat transfer, specifically in the case of hyperthermia, could be Pennes model, “providing its use is based on some insights gained from the studies described here.”
I personally found this article interesting because we talked about this in bio-mechanics. Not necessarily for hyperthermia in tumors but for modeling the vasculatures bio-heat transfer with Penne’s model. We have talked a lot about how many people misuse these models and as engineers we are to be very careful. Well this article showed how even Penne’s model can be misused. Very interesting stuff!
--Andrew Stewart
http://ieeexplore.ieee.org/Xplore/login.jsp?url=/stamp/stamp.jsp?arnumber=284920&isnumber=7050

Penne's Bio-heat model... not sufficient, or is it...

One method of treating tumors is by use of hyperthermia. In order to implement this treatment a sufficient understanding of the attendant thermal processes in diseased and normal tissue must be attained. It is vital to be able to predict, measure, and interpret the tissues thermal and vascular response to heating appropriately if one is going to use such a treatment. The problem lay herein, living tissue morphology is of a complex nature, and thus modeling of its properties can be quite difficult. In studies past, researchers have used some simplifying assumptions that would presume to be needed. However, there have been investigators recently who have argued that “Penne’s interpretation of the vascular contribution to heat transfer in prefused tissues fails to account for the actual thermal equilibration process between the flowing blood and the surrounding tissue and proposed new models, presumably based on a more realistic anatomy of the perfused tissue” (Holmes,K.R, Arkin, H. Xu, L.X.).
This article gives an analytic comparison of several new bio-heat transfer models and places specific focus on the problems “of their experimental validation.” Since there is very little measuring equipment able to map out the tissues properties with all its variations at the spatial scale of blood vessels (i.e. diameters of less than .2 mm), the new models lack experimental support and thus are subject to error. All and all, the best way to map this bio-heat transfer, specifically in the case of hyperthermia, could be Pennes model, “providing its use is based on some insights gained from the studies described here.”
I personally found this article interesting because we talked about this in bio-mechanics. Not necessarily for hyperthermia in tumors but for modeling the vasculatures bio-heat transfer with Penne’s model. We have talked a lot about how many people misuse these models and as engineers we are to be very careful. Well this article showed how even Penne’s model can be misused. Very interesting stuff!
--Andrew Stewart
http://ieeexplore.ieee.org/Xplore/login.jsp?url=/stamp/stamp.jsp?arnumber=284920&isnumber=7050

Waving at Thrombosis

Clots in arteries and veins are the main cause of heart attack, stroke, and pulmonary embolisms. The occurrence of thrombosis is rising and potential methods to treat the condition fast and effectively are pouring in. Yet not all are as successful as hoped. Although, researchers at Emory University say that using ultrasound waves in combination with clot-dissolving drugs aid in rapid treatment for both acute in-situ arterial thrombosis and deep vein thrombosis. Using this method, the researchers we able to break up and dissolve blood clots, restore flow, and prevent valve damage just as traditional methods used today. The significance of the treatment is the speed at which the clots are removed and the efficiency of removing the clots relative to previous treatments. The addition of ultrasonic waves to the treatment loosens the proteins in the blood clot. This causes the clot to become more permeable to the drugs and allows them to enter the clot easier and faster. This is especially useful in deep vein thrombosis due to the necessity for quick treatment upon diagnosis. In DVT, the clot rests deep in the lower leg or thigh and has high probability to cause fatal pulmonary embolisms. This treatment is an effective way to reduce the possibility of these embolisms. The study at Emory showed 100% percent of patients with acute in-situ arterial thrombosis had their clots dissolved and 87% of DVT patients had their clots dissolved.

http://www.sciencedaily.com/releases/2008/11/081123150253.htm

Antioxidants 'cannot slow ageing'

Using Nematode worms, scientists found those given enhanced antioxidant powers to deal with tissue damaging "free radicals" did not live any longer.
Antioxidants are a staple of the beauty and health industries, based on the theory that ageing is caused by a build-up of molecular damage caused by reactive forms of oxygen, superoxides or free radicals, circulating in the body, causing oxidative stress. Antioxidants supposedly worked to mop up these free radicals, minimising their damage.
This new study, however, could explain why many studies aimed at proving the theory have been inconclusive.

Nematode worms, are useful tools for scientists who want to explore how our bodies work, because they share many genes with humans, and they have a lifespan measured in days, allowing scientists to get better clues about long-term changes.
The UCL team, led by Dr David Gems, genetically manipulated nematodes so that their bodies were able to "mop up" surplus free radicals. This is theory, should give them an advantage over normal nematodes in terms of ageing and lifespan. However, these worms lived just as long as the others, suggesting that "oxidative stress" is less of a factor in the ageing of our cells and tissues as some have suggested.

Dr. Gems stated that: "It is clear that if superoxide is involved, it plays only a small part in the story - oxidative damage is clearly not a universal, major driver of the ageing process."
He said a healthy, balanced diet was important for reducing the risk of many "old age" diseases, such as cancer, diabetes and osteoporosis, but there was no clear evidence that eating antioxidants could slow or prevent ageing, and even less evidence to support the claims made by antioxidant pills and creams.

I found this article interesting because we spent along time one class session, in association with a SNBAL, discussing free radicals and the theory of antioxidants. Also, preventing the looks of aging is a concern for many people, and while may not be the most pertinent to me or my peers right now, it will definitely become more relevant to us in the next decade or so.

http://news.bbc.co.uk/2/hi/health/7754644.stm

Slowing Down AIDS

The AIDS pandemic is not an issue to be taken lightly. It affects over 30 million people worldwide and its incidence of infection only seems to be growing. AIDS is actually the symptoms that stem from the human immunodeficiency virus, otherwise known as HIV. There are many treatments that aim to slow down the virus, but none have proven to eradicate it completely. While Dr. K. Sandeep Prabhu has not found the cure, he has added a new weapon to the field to combat the progression of the virus. He states that he has “found that increasing the expression of proteins that contain selenium negatively affects the replication of HIV.” In other words, increasing the manufacture of these proteins already found in blood slows down how fast the virus can replicate. This declaration proves to be somewhat of an understatement, as the results show that the reproduction is slowed down by at least 10-fold. Ultimately, the increase in these proteins will cause a decrease a key protein produced by the HIV virus known as Tat, which just so happens to play a critical role in replication. Not only did the research team test their hypothesis by increasing the selenium proteins, but also reducing their occurrence. In this case, when the researchers reduced the selenium proteins, the virus was able to replicate more than three times as much. Both trials suggest that there is a direct correlation between the selenium proteins and the speed at which the virus can reproduce. As a student who has always been drawn towards diseases that affect large populations, this discovery sparked my interest. It has always amazed me that with all the information and knowledge that have on such viruses that a permanent cure has not been discovered. Though not curing the disease entirely, this exciting new find will eventually lead to more effective drugs that have a dramatic effect on the life spans of those infected.

http://www.medicalnewstoday.com/articles/131174.php

“Mirus Bio Announces Delivery Technology Breakthrough for RNAi Therapeutics”

Alex Warren
Blog #3
“Mirus Bio Announces Delivery Technology Breakthrough for RNAi Therapeutics”

Researchers at Mirus Bio Corporation have developed a method for literally turning off genes inside proteins that can cause certain types of cancer, viruses and other types of metabolic diseases. The technique is abbreviated RNAi, which stands for RNA interference. This RNAi is basically a silencing switch they find on proteins that they can ‘switch’ to stop the production of mal-proteins. However, RNAi has not been able to be used inside key cells that could really do damage to the disease, and still has not been engineered to treat inside tumors. The interesting thing here is that, “Mirus researchers have overcome these problems by assembling tiny synthetic molecules, called Dynamic PolyConjugates(TM), that shield their genetic cargo as they home in on target cells.” “The Dynamic PolyConjugates' "cargo" consists of small pieces of genetic material known as small interfering RNA sequences ("siRNA"), which blocks a cell's RNA.” Since the cell’s RNA is blocked, the blueprints for creating proteins never reach the ribosomes, thus terminating the expression for a particular gene. SiRNA’s can be genetically engineered to turn off the expression for any gene for which the sequence is known. Usually, siRNA’s are destroyed naturally by the body before ever reaching the RNA, creating a problem. However, Mirus Bio have coated the siRNA’s with a polymer that “not only protects the siRNA in the bloodstream, but also enables it to break out of a cell's endosome.” This way, it can interact with the mRNA!
Link:http://www.lexisnexis.com/us/lnacademic/results/docview/docview.do?docLinkInd=true&risb=21_T5262502221&format=GNBFI&sort=RELEVANCE&startDocNo=1&resultsUrlKey=29_T5262502227&cisb=22_T5262502226&treeMax=true&treeWidth=0&csi=246798&docNo=1

“Mirus Bio Announces Delivery Technology Breakthrough for RNAi Therapeutics”

Alex Warren
Blog #3
“Mirus Bio Announces Delivery Technology Breakthrough for RNAi Therapeutics”

Researchers at Mirus Bio Corporation have developed a method for literally turning off genes inside proteins that can cause certain types of cancer, viruses and other types of metabolic diseases. The technique is abbreviated RNAi, which stands for RNA interference. This RNAi is basically a silencing switch they find on proteins that they can ‘switch’ to stop the production of mal-proteins. However, RNAi has not been able to be used inside key cells that could really do damage to the disease, and still has not been engineered to treat inside tumors. The interesting thing here is that, “Mirus researchers have overcome these problems by assembling tiny synthetic molecules, called Dynamic PolyConjugates(TM), that shield their genetic cargo as they home in on target cells.” “The Dynamic PolyConjugates' "cargo" consists of small pieces of genetic material known as small interfering RNA sequences ("siRNA"), which blocks a cell's RNA.” Since the cell’s RNA is blocked, the blueprints for creating proteins never reach the ribosomes, thus terminating the expression for a particular gene. SiRNA’s can be genetically engineered to turn off the expression for any gene for which the sequence is known. Usually, siRNA’s are destroyed naturally by the body before ever reaching the RNA, creating a problem. However, Mirus Bio have coated the siRNA’s with a polymer that “not only protects the siRNA in the bloodstream, but also enables it to break out of a cell's endosome.” This way, it can interact with the mRNA!
Link:http://www.lexisnexis.com/us/lnacademic/results/docview/docview.do?docLinkInd=true&risb=21_T5262502221&format=GNBFI&sort=RELEVANCE&startDocNo=1&resultsUrlKey=29_T5262502227&cisb=22_T5262502226&treeMax=true&treeWidth=0&csi=246798&docNo=1

Rewiring Of Brain Responsible For Baffling Chronic Pain

Many patients suffer from chronic pain which is a a disease that occurs when pain is present after the injury has healed. When they studied people with normal brains and compared them to those that are suffering they discovered that the areas of the brain that are responsible for pain, temperature and emotion looked like someone had rewired them. This study was done at Northwestern University and these patients were diagnosed with what is called Complex Region Pain Syndrome (CRPS). This study was done with a total of 44 patient, 22 normal and 22 suffering.
This disease begins with a serious injury to the hand or foot and then radiates to the arm or the entire body at times. This only occurs in about 5% of patients as the pain usually goes away after the injury heals in 95% of patients. The skin usually turns either blue or red and the temperature of the body goes from hot to cold. They discovered that the rewiring occurs in the white matter of the brain unlike they had thought for many years that it happened in the gray matter. Patients have also been suicidal as the pain has become extreme. Many patients were not believed at first but now have been taken very seriously.
The significance of this discovery is of great importance because physicians can now try and find pharmaceutical drugs that will treat the white matter neurons of the brain and not the gray matter neurons like they were previously doing.
This is very interesting to me because we have just finished studying neurophysiology and it is interesting how the brain can even seem to rewire itself regardless of pain. This discovery can lead to many positive findings and can also help save the some 200,000 people that suffer from this disease.

Jonathan Dougherty

http://www.medicalnewstoday.com/articles/131081.php

Sporadic Breast Cancer

Breast cancer is the most commonly occurring cancer in women. Non-hereditary, sporadic breast cancer is the most widespread, representing 85 to 90% of all cases. Despite its occurrence, it remains the least well-known type. Researchers at CNRS and CEA, working with a team from Hôpital Saint-Louis in France, have just discovered the cause of 50% of sporadic breast cancers.
More than four out of five breast cancers are not related to hereditary factors. The sporadic cases are due to causes which were, until recently, poorly understood. On the other hand, hereditary forms of cancer, which represent only 10 to 15% of breast cancers, have for years been the subjects of studies, work which has resulted in the identification of ten genes whose mutation increases the risk of cancer in an individual.
Among these genes, nine are involved in the DNA damage response system, which is the collection of cell mechanisms that optimize the repair of DNA. The tenth gene codes for a protein which inhibits the action of the AKT1 enzyme. And among these ten genes, two are responsible for 50% of hereditary breast cancers: BRCA1 and BRCA2. Researchers from the "Radiobiologie moléculaire et cellulaire" (CNRS / CEA) lab took these data on hereditary cancers as the starting point for their research into non-hereditary forms.
Researchers have been trying to prove whether or not there is a link between hereditary and sporadic cancers. They found that AKT1 protein is over-expressed in 50% of sporadic breast cancers. They were able to show that activation of AKT1 leads to the sequestration of the BRCA1 protein in the cytoplasm. This makes it impossible for the protein to penetrate the nucleus, which prevents it from fulfilling its role in DNA repair. The cell then behaves as if it had no BRCA1 gene, without involving a mutation (unlike hereditary forms, where the BRCA1 gene undergoes an alteration). This phenomenon is observed in 50% of sporadic tumors. These results show a single, previously undetected, link between sporadic and hereditary cancers: the DNA damage response system.

http://www.sciencedaily.com/releases/2008/11/081121081059.htm

The Catch-22 of Aging

In yeast cells, there is a protein called Sir2 that repairs breaks in its DNA. But when Sir2 goes to repair the DNA, it leaves its other function of inactivating a sterility gene elsewhere in the yeast. In the end, yeast cells have relatively undamaged DNA, but they are sterile, a sign of aging in the fungi. It has been questioned if the mammalian equivalent of Sir2, SIRT1, caused the same genetic effect. Experiments on mice show that SIRT1 has similar effects as Sir2, except that it may also cause many other age-related problems, such as diabetes and dementia. Though, when mice were fed SIRT1, they lived 25 days longer than the control group of mice. There is still much research and experiments going on with the protein and other simple organisms like yeast.

This is an interesting thing to keep tabs on, because who, generally speaking, doesn’t want to live longer? One thing that doesn’t make sense is that if you simply increase the amount of Sir2 or SIRT1 in cells, won’t the Catch-22 effect no longer be a problem. I guess if it were that simple they would have solved the problem already. Maybe the issue is determining how the Sir2 or SIRT1 protein changes its function within the cell. Hypothetically speaking, if this research accomplishes all that I’m sure it is trying to. Soon, a new diet trends will emerge, featuring things like: “Now with SIRT1!” or some other crazy slogans. This will increase the longevity of life, but will it cause some unknown effects down the line? Such as an emergence of a new, overpopulation, or the cause of a known disease, such as medicines that are recalled because they caused adverse effects. Maybe we'll be seeing this in nutritional values sooner than we think.

http://sciencenow.sciencemag.org/cgi/content/full/2008/1126/1

Genetic Testing for Child's Potential Sports Abilities?

Atlas Sports Genetics is offering a test that supposedly predicts a child’s natural athletic abilities. For $149, a doctor swabs inside the child’s cheek along the gums to gather DNA. They test for ACTN3 to determine if the child would be better at endurance sports (distance running), speed and power sports (sprinting, football), or both. Genetics

wants to test children from infancy to 8 years old as the physical tests for future sports performance is better at that age range than later on.

Obviously there are some ethic questions as to whether or not parents should test their kids. They could use these results to force their children into a specific sport or to just let the child choose. Another problem is the fact that many different genes contribute to the major athletes’ (Michael Phelps, Usain Bolt) abilities, so testing for one gene can’t tell all. Most researchers agree that after specific training for their body types, the gene might make a difference between world class athletes but not for “Johnny” or “Suzie” who play soccer or field at middle school levels.

Focusing in on the ACTN3 gene, most of the research was based in Australia. They looked at the gene’s combinations from each parent. The R variant codes for the protein alpha-actinin-3 which is specific to fast-twitch muscle. The X variant codes for prevention of that protein. Testing 429 elite white athletes found that 50% of the 107 sprint athletes had 2 copies of the R variant. No female elite sprinter had 2 copies of the X variant. All male Olympians involved in the power sports had 1 R variant minimally. As for the endurance sports, 25% of those athletes had 2 copies of the X variant, whereas the control group had 18% so people with 2 copies of the X variant are more likely to be best at endurance sports.

Some people believe in this test's results while others say the best way to tell is to “just line them up…for a race and see which ones are fastest.” Obviously, you cannot pick out the next Michael Jackson based on a test on a 5 year old, but many people believe you could nurture the child with careful nutrition, coaching, planning, and competition.

http://www.nytimes.com/2008/11/30/sports/30genetics.html?pagewanted=1&_r=1&no_interstitial

Nanotechnology Focus Shifts to Shape, Not Size

The advent of nanotechnology applications in medicine, especially in drug delivery, was motivated by the belief that minimizing the size of drug delivery vehicles would optimize their effectiveness. A research team from the University of North Carolina- Chapel Hill made a surprising discovery about the effectiveness of nanoparticles that contradicts such traditional beliefs. According to Joseph DeSimone and his research team, it’s not size that determines the immune response to nanoparticles, but rather their shape. Research suggests that rodlike particles are able to infiltrate target cells more effectively, largely due to decreased macrophage response. Conventional spherical nanoparticles are easily picked up by macrophage activity because they don’t require much expansion by the specialized immune cells. Therefore, engulfing elongated shapes from the side is much harder. It’s also very unlikely that the macrophage would attack the nanoparticle from one end because it is only a small fraction of the particle’s total surface area. The exact proportions of the rodlike nanoparticles can vary to target specific cells or block entrance into areas subject to damage from a certain drug.

This revolutionary discovery will have a profound impact on the nanotechnology industry. The focus now has shifted from making medical nanobots smaller and smaller to specifying a shape for each unique application. More research is required to determine the ideal shape for each target cell type, but the new information will help bioengineers successfully implement nanotechnology in the future.

Scientific American Article:
http://www.sciam.com/article.cfm?id=size-shape-matter-nanotech-drug&page=2

~Angie Burrer
Section 501

Antioxidants 'cannot slow ageing'

Scientists from University College London found in a study that Nematode worms with enhanced antioxidant powers did not live longer compared to the normal nematodes. In 1956, it was suggested that the cause of ageing was molecular damage caused by reactive forms of oxygen, called free radicals, circulating in the body. Antioxidants apparently worked by eliminating the free radicals. However, the study involving nematode worms raises new questions.

In the study, nematode worms were genetically manipulated to eliminate the surplus of free radicals. In theory, the modifications should give them an advantage over the normal nematodes in terms of ageing and living longer. Nevertheless, the results indicate that there were not significant differences between the worms, suggesting that free radicals are not the main cause of aging. The leader of the UCL team, Dr David Gems, said: "The fact is that we don't understand much about the fundamental mechanisms of ageing - the free radical theory has filled a knowledge vacuum for over 50 years now, but it doesn't stand up to the evidence. It is clear that if superoxide is involved, it plays only a small part in the story - oxidative damage is clearly not a universal, major driver of the ageing process." According to the study, there is not clear evidence suggesting that eating antioxidants could slow or prevent ageing. Other scientists believe that the results from the study using nematodes may not be relevant to the process of aging in humans.

Sources: http://news.bbc.co.uk/2/hi/health/7754644.stm

Javier Garza

Ties Between Cholesterol Drugs, Muscle Problems Studied By MSU Researcher

In Michigan State University, they are researching whether the most popular class of cholesterol-lowering drugs like Lipitor, Crestor and Torvast may cause muscle problems in users. These statins can have an effect on skeletal muscles causing them to be weak, fatigue, or deteriorate.

Statins work by preventing cholesterol from forming. This is good in structures like liver cells, but it can be problematic in places such as muscle cells. Almost 50 percent of all Americans over the age of 50 are prescribed a statin medication, and use has tripled over the past 7 years.

A previous statin, Baycol, was taken off the market in August 2001 after it appeared to be responsible for 31 deaths through a potentially fatal breakdown of muscle tissue known as rhabdomyolysis.

In the study, nuclear magnetic resonance imaging will be used to measure muscle integrity and function before and during statin treatment. “While statins have tremendously helped millions of Americans lower their cholesterol and improve their cardiac health, we need to be confident we are not causing other problems in the body,” said Jill Slade, assistant professor of the radiology and osteopathic manipulative medicine at MSU.

I found this article interesting, because we are learning about muscles in physiology. Also, most of the foods I enjoy have high levels of cholesterol in them, and one day, I will probably be on these drugs, just like my entire family over the age of 50.

Daniel Grunden
http://www.medicalnewstoday.com/articles/129144.php

New Hope for Down's Syndrome

As of now, there is no definite cure for patients with Down's Syndrome, but according to research (conducted on mice) from the National Institute of Health in Bethesda, Maryland, there could be a way to ease the symptoms and problems associated with the disease.
Some of the major issues that develop in Down's Syndrome patients are higher heart rate, developmental problems, and learning disabilities. These difficulties are thought to be caused by a low production of two proteins: NAP and SAL; this activity stems from a defect in a certain type of brain cell caused by the inherited extra chromosome. Knowing this, scientists injected these proteins into mice pregnant with pups having an extra copy of a segment of one of their chromosomes. As seen in babies with Down's, the pups inside the womb (before the protein injection) were seen to develop more slowly than normal pups. However, after birth, the pups, now with altered levels of the key proteins, reached their "developmental milestones" at the same rate as normal mice, and the level of another typically under-produced protein was normal. Researchers are now observing later development of these mice to see if the effects of this treatment are long-lasting (or even permanent).
If this kind of early developmental treatment proves to be feasible for humans, it would have a great impact on people with Down's Syndrome. With more and more children being born with this disease (parents are encouraged by the increasing life expectancy for Down's children), halting the major problems that come with it would improve their overall quality of life.
Since this research has only been conducted on mice, there is no certainty that it will be effective on humans.

http://news.bbc.co.uk/2/hi/health/7749883.stm
http://news.bbc.co.uk/2/hi/health/medical_notes/1254702.stm

Rewiring Of Brain Responsible For Baffling Chronic Pain

New finding by scientists at Northwestern University's Feinberg School of Medicine begin to explain the causation of the mysterious condition of chronic pain. When looking into the brains of people with a baffling chronic pain condition, they discovered that their brains looked as if the areas related to emotion, pain perception and the temperature of their skin has been "rewired". Complex region pain syndrome (CRPS.) Is a pernicious and nasty condition that usually begins with an injury causing significant damage to the hand or the foot. For the majority of people, the pain from the injury disappears once the limb is healed. However, for 5 percent of the patients, the pain rages on long past the healing, sometimes for the rest of people's lives. About 200,00 people in the U.S. have this condition.The physiological changes take place in the brain's white matter. These changes cause the gray matter to atrophy. White matter reorganization is related to intesnsity and duration of their pain. It is unknown if CRPS causes these changes or if these people have preexisting abnormalities that make them more predisposed to experience these changes.

http://www.medicalnewstoday.com/articles/131081.php

Microchips for Memory

If you've ever considered yourself a nerd (a computer nerd to be exact), then you may have seen a small movie called "Johnny Mnemonic". Based off a William Gibson short story, the film stars Keanu Reeves as a transporter who hides digital information on a computer chip lodged in his brain. Not only did the movie get bad reviews, but the whole idea of putting microchips in someone's brain was considered absolutely ludicrous. However, professors at the Center of Neural Engineering at the University of Southern California are currently working on a silicon chip that mimics the hippocampus, which is know for creating memories. If the project is a success, then it could replace the hippocampus altogether and help those with memory loss disorders.

The hippocampus is not responsible for storing long-term memories. It is, however, responsible for converting short-term memory input into long-term memory output. It's also the part of the brain most commonly affected by head trauma, strokes, epilepsy and Alzheimer's. At the moment, there have been no medical advances to clinically treat damage to the hippocampus.

The researchers began by studying the hippocampus of rats, keeping them alive in certain nutrients. By stimulating the neurons with random computer generated signals and observing the outputs, the scientists were able to find sets of mathematical functions that transform any input into a specific output similar to the hippocampus.

As of right now scientist are predicting at least half a decade before applying their work to humans. However, memory chip prototypes today have a 95% successful input/output pathway, so it won't be long before Johnny Mnemonic comes to life.

Source:

http://www.wired.com/medtech/health/news/2004/10/65422

Fast Food: A Potential Risk Factor for Alzheimer's

A recent study in Sweden has shown that diets high in fat, sugar, and cholesterol can possibly lead to the development of Alzheimer’s disease. The study was performed on mice that were genetically modified to mimic a gene common in Alzheimer’s patients, apolipoprotein E, also known as apoE4. ApoE4 controls the transport of cholesterol.
During the study conducted by Susanne Akterin, the genetically altered mice were fed diets that mimic the nutritional content of fast food, that is diets rich in sugar, fat, and cholesterol. After nine months, their brains were examined and revealed that they were had an increase in the phosphate groups attached to a substance that forms the characteristic neurofibril tangles in the brains of Alzheimer’s patients. The tangles inhibit normal cell functions, ultimately leading to their death. High cholesterol diets also were found to reduce the levels of Arc, a protein involved in memory storage.
This study ultimately confirms that a combination of diet and genetic factors lead to the development of Alzheimer’s disease. I found this article interesting because as college students, we tend to eat diets high in sugars and fats. Depending on our genetic make-up, our diets now could potentially lead to the development of this disease later in our lives.

http://www.sciencedaily.com/releases/2008/11/081128082937.htm

Harvard Scientists Unravel the Secret of Aging

Scientists at Harvard University have pinpointed a potential element in determining how we age, and perhaps even how to reverse the effects of aging altogether. Their studies involve sirtuins, proteins that play an important role in the aging process. However, their primary function is to manage gene regulation, turning them “on” and “off” as necessary.
As we grow older, our DNA damage reaches a level that the repairing sirtuins cannot keep up with. Overwhelmed, the sirtuins increasingly neglect their first task of gene regulations, leading to age acceleration.

To hinder or reverse this process of aging, the Harvard scientists used resveratrol, a chemical found in red wine and certain nuts, peanut butter, and grapes, which appears to activate the sirtuins so that they become more efficient and even better with gene regulation, thus slowing the effects of aging. When resveratrol was inserted into mice, their lifespan increased by 24 to 46 percent, and improvements appeared in conditions such as cataracts, osteoporosis, and decline in motor skills. This technique is yet to be tried in humans, but the results shown from the mice indicates a strong possibility that resveratrol may have the same effect in humans.

By continuing to study the effects of resveratrol, Harvard scientists predict that anti-aging drugs are not far in the future, and also hope to develop drugs that will combat Alzheimer’s, other degenerative diseases and possibility even some cancers.

Nanomachine Kills Cancer Cells

Nanomachine Kills Cancer Cells

Researchers at UCLA have created a nanomachine that can take up and store anticancer drugs inside pores and then release them on command with response to light. This is known to be the first device that is light powered and capable of going inside a living cell. The researchers at UCLA used a special material known as mesoporous silica to build the nanomachines and coated the inside of the pores with azobenzene. The reason that this method works is because azobenzene responds to specific wavelengths of light by changing its conformation. As the conformation of azobenzene is changed, this causes the pores to release their contents: the anticancer drugs. It has also been shown that the release of the drugs can be monitored precisely. Researchers have found that by altering the wavelength, intensity, and excitation time, they can precisely regulate the exact time that the pores release their contents.

This method has been successfully tested in vitro on many different types of cancers including pancreatic and colon cancer. The nanomachines were given to human cancer cells in vitro and taken up by them in the dark. They found that when they shined the light on the nanomachines, the anticancer drugs were released on command; it was like they were using a remote control. The head of this research believes that the real achievement is the fact that they proved that they were able to control the precise amount of drug that was released based on the light intensity. The researchers were also thrilled that the cancer cells readily took up these nanomachines. This invention could potentially open up a whole new approach to cancer treatment using phototherapy. The advantage to this type of treatment is obviously that it is much more precise than the current technology and will not kill any cells besides the cancerous ones.

I found this article interesting because of the fact that we just did our device design projects and one of the struggles for our group was figuring out how we were going to precisely control the nanobot. This technology presents a method that would be very effective for nanobot control. I was also interested in this new technique to cancer treatment. It seems that if this type of treatment were perfected, then phototherapy would always be preferred to the current type of treatment.

http://www.sciencedaily.com/releases/2008/04/080401095236.htm

The Bond Breaker

Recent study into physiology and biology has allowed science to determine what causes certain diseases, but unfortunately creating a compound that treats the disease is a whole other issue. Presently, chemists start with a base molecule and add or subtract atoms one by one. This is very inefficient with on about 8 percent of the starting material being converted into a usable drug.

Fortunately Melanie Sanford of Michigan University has developed a custom made catalyst which breaks down the C-H bond, allowing for any chemical she specifies to bind after that. Because the C-H bond is one of the most common bonds in organic chemistry, this catalyst grreatly speeds up drug synthesis and molecule building.

The catalyst, which is a modified basic bond breaker, has been changed by adding nanosized structure to make it react only with the desired C-H bond. The catalyst also contains the molecule intended to replace the C-H group, greatly increasing efficiency.

Using this new catalyst, chemical engineers could now use flourine in their compounds. Flourine is an attractive component of new drugs because it breaks down slowly in biological systems, but the reason it has not been used previously was that it is extremely difficult to add or remove the element from starting materials.

Gas companies are also estastic about this discovery because by changing one C-H bond in methane, it becomes liquid methanol, which has the same energy output as methane but is much easier to transport. All that's left to do is manufacture this catalyst on the million ton scale and it would "impact ... the world right away."

http://www.popsci.com/melinda-wenner/article/2008-10/bond-breaker

World's Oldest Person Dies

Just how old does one have to be to hold the title as the world's oldest person?

Edna Parker, formerly named the world's oldest person over a year ago, died at age 115. UCLA gerontologist Dr. Stephen Coles currently maintains an active list of the world's oldest people and was notified that Parker died Wednesday at a nursing home in Shelbyville, Indiana. She was 115 years, 220 days old. Coles then confirmed that Parker was the 14th oldest validated supercentenarian in history. However, with her death, Maria de Jesus of Portugal, born Sept. 10, 1893, is now the world's oldest living person, according to the Gerontology Research Group.

Parker was born April 20, 1893, & had been recognized by Guinness World Records as the world's oldest person since the death of Japan-native Yone Minagawa, who was four months older, in 2007. Parker was widowed when her husband, Earl Parker, died in 1939 of a heart attack, lived alone in their farmhouse until age 100, moved into a son's home, and then resided in a Shelbyville nursing home.

She never drank alcohol, never tried tobacco, and led an active life. The only advice that she openly gave others concerning the possibility of a longer life was "more education." Parker outlived her two sons, Clifford and Earl Jr. She had five grandchildren, 13 great-grandchildren and 13 great-great-grandchildren. One of her grandsons, Don Parker, 60, said his grandmother had a small frame and a mild temperament. She walked a lot and kept busy even after moving into the nursing home, he said. "She kept active," he said Thursday. "We used to go up there, and she would be pushing other patients in their wheelchairs."

So, even with improved physiological understandings and the resulting advances, it cannot hurt to take such stories into consideration. Even with the available physiological help, it would prove a reliable basis for one's life to live healthy and remain active.


http://news.yahoo.com/s/ap/20081128/ap_on_re_us/obit_oldest_person

Fast Food A Potential Risk Factor For Alzheimer's

A connection between the food you intake and the development of a neural disorder? That’s exactly what the research at Karolinska Institutet in Europe suggests. Most humans with Alzheimer’s contain the gene apoE4, which is a variant of the gene that functions to transport cholesterol. The scientists at Karolinska Institutet worked with mice by mimicking the effects of the apoE4 gene in humans. The mice were then fed a diet that was high in fat, sugar, and cholesterol for nine months, representing fast food intake. This study focuses on the increase of phosphate groups attached to tau, which forms the neurofibrillary tangles found in patients with Alzheimer’s. The increase in fat in cholesterol in one’s diet leads more of these neurofibrillary tangles to be formed. These tangles reduce the ability of the cells to function and will eventually lead to their death.

Exactly what type of food is best? Studies have shown that those who on the Mediterranean diet, which consists of a lot of fruits and vegetables and little meat are less likely to develop Alheimer’s or its preliminary phases than those who eat meals high in fat and cholesterol. This study shows an important connection between diet and Alzheimer’s and may be able to prevent some cases. Say if someone knows that they contain the variant gene apoE4 then they need eat healthier to avoid the chances of developing Alzheimer’s.

http://www.medicalnewstoday.com/articles/131218.php
http://www.cbsnews.com/stories/2006/10/09/health/webmd/main2076123.shtml

Roger Jordan
VTPP 434-501

Defective Calcium Metabolism in Nerve Cells Contributes to Neurological Disorder

Spinocerebellar ataxia 3 (SCA3) is a rare condition in which the patient’s coordination, speech, and vision are impaired, and causes atrophy of the brain. This rare genetic disease is otherwise known as Machado-Joseph disease and is mostly seen in people with Portuguese heritage. SCA3 displays similar conditions as Huntington’s disease.

SCA3 and Huntington’s disease are caused by disturbed calcium signaling within nerve cells. This is due to repeating segments of DNA which affect the amino acid code, causing a repetition of units of glutamine in the mutated proteins. The more often the repeats occur, the earlier the disease starts to affect the patient.

Researchers have found that in the presence of the mutated protein ataxin-3, calcium is released from the endoplasmic reticulum. In normal ataxin-3, stored Ca2+ is not released.

Such high levels of calcium in a cell are toxic and lead to impaired motor function. Researchers found this to be a similar case in genetically engineered knock out mice with over expressed human ataxin-3 protein. The mutant mice displayed signs of brain deterioration in the same regions of the brain as patients with SCA3 and Huntington’s.

Researchers then gave these knock out mice Dantrolene, an emergency treatment for humans if a patient reacts to anesthesia, to determine if it would block the excessive amount of calcium release in skeletal muscle cells. Dantrolene is only allowed to be used once due to the side effects. They found this treatment to lessen the symptoms of the over expressed ataxin-3 protein.

The conclusion of this research was not that Dantrolene was the answer to curing SCA3 and Huntington’s due to its side effects. They concluded that they could make a more precise drug that would block Ca2+ release from the ER of skeletal muscle cells, improve the coordination skills and slow brain atrophy of patients suffering from SCA3 and Huntington’s disease without causing the side effect of Dantrolene. This research has also been used to study other neurodegenerative diseases.

I found this article to be interesting enough to share because it pertains to the material about skeletal muscles we just covered in class. This article discusses how the amount of calcium in cells determines the functions of cells. This research is important to our medical society because it allows us to better understand what causes some neurological diseases.

http://www.news-medical.net/?id=43480

New Less Invasive Down's Syndrome Test Created

Down's Syndrome, also known as Trisomy 21, is a genetic disorder caused by a third copy of the twenty first chromosome. Down's is generally associated with a decrease in cognitive function along with an impairment to physical development. Diagnostic tests have been available for years. The problem with these tests is that they carry a relatively high risk of miscarriage.  There are two main methods that are currently used; the first requires a drawing of amniotic fluid a carries a 1 in 100 chance of miscarriage. The second, which offers a worse 1 in 50 chance of miscarriage, utilizes chorionic villus sampling, taking a tissue sample from within the womb. 

Because of these high risks, a new method has been developed by Stanford University. This method requires just a blood sample from the mother. Known as a "shotgun sequencing test," the method sequences the mother's genes. DNA from the baby is found in the mother's blood through the placenta. The trial, which was done on 18 women was extremely successful, correctly identifying even the smallest amount of increase of the 21st chromosome.  The next step is a larger study but this method could easily be implemented in the next few years, allowing parents to know as soon as possible. 

BBC     

Infrared Light That Reverses Dementia

The concept of shining light onto the skull and essentially eliminating the debilitating affects of dementia and Alzheimer's may seem a little farfetched, but researchers from the University of Sunderland led by Dr. Gordon Dougal believe that this method has a fighting chance. This technology has the potential to be an enormous scientific breakthrough, in that the current treatments for this condition merely slow the rate of deterioration of the brain, while the infrared treatment promises to stop the deterioration as well as partially reversing the process altogether.

“As we get older, cells stop repairing themselves and we age because our cells lose the desire to regenerate and repair themselves. This ultimately results in cell death and decline of the organ functions, for the brain resulting in memory decay and deterioration in general intellectual performance. But what if there was a technology that told the cells to repair themselves and that technology was something as simple as a specific wavelength of light? Near infrared light penetrates human tissues relatively well, even penetrating the human skull, just as sunlight passes through frosted glass.” The specific wavelength of light for this type of procedure would be 1072 nm, a wavelength that occurs naturally in sunlight, and is not harmful in moderation. The idea for this technology was derived from a previous treatment, developed by Dr. Dougal, for the elimination of cold sores. The infrared light stimulates the cells to grow and attack the virus causing a removal of the sore, so the concept of growth stimulation was extended to the brain.
One in three people will end their lives with a form of dementia.

The treatment itself will consist of the patient wearing the specifically designed helmet, consisting of 700LED lights that emit the 1072 nm infrared light, for periods of merely 10 minutes a day. The picture on the right is of the prototype helmet that is will be tested in the future. Although there has not been full scale human testing done, one family was willing to try the procedure in desperation. Clem Fennel was 57 years old and a victim of chronic dementia. He was unable to speak upwards of one syllable, couldn't answer the phone, and couldn't be left unattended. Upon recieving the treatment for 10 minutes daily, the family saw drastic changes in just three weeks. He became able to hold conversations, go to the store by himself, and his wife said that he finally had his personality back. This process changed the family's lives forever, and has the potential to do the same for many more.

One in three people will end their lives with a form of dementia. Around 700,000 suffer from dementia - with more than half having Alzheimer's disease. With this new technology the numbers could be significantly lowered, and many family's will be changed for the better. The infrared helmet technology essentially has the ability to reverse the effects of dementia and Alzheimer's disease only through the power of light.

One step closer to a cure for AIDS

AIDS is a devastating disease that 2 million people die from every year. So far, no successful cure has been found but doctors in Berlin, Germany are hopeful after curing a man of the AIDS virus by an unlikely source. The patient, an American living in Berlin had contracted the virus yet also had leukemia. When his conditions with leukemia worsened the doctors performed a bone marrow transplant. He had to stop treatment of his AIDS medication to continue with the transplant. The stem cells from the transplanted marrow contained genes resistant to the virus. The cells contained a rare genetic mutation known as CCRS, which keeps the virus from attaching to infected cells. To the doctors surprise, after 20 months not only was the patient free of leukemia but there was also no trace of AIDS. Although the doctors stressed that this cannot become a regular treatment for AIDS, many are hopeful that this will open doors to new possibilities in gene therapy and move one step closer to a cure. Many are researching this case to find answers to possible cures. While a cure might not be here today, one may be looming around the corner.

http://www.abc.net.au/news/stories/2008/11/14/2420169.htm?section=world

Short Term Effects of C-Section

A recent study published in the The Journal of Child Psychology and Psychiatry looked at the neurohormonal differences of mothers having just delivered their babies naturally and through a Caesarean section. The study looked at how responsive and attached mothers were to the sound of their babies voice immediately after childbirth. Using brain imaging scans, the researchers concluded that in mothers having delivered naturally showed significantly greater responses in several parts of their brains related to "sensory processing, empathy, arousal, motivation, and reward/habit-regulation" in hearing their baby's voice for the first time.

As the researchers explain: "The experience of childbirth by vaginal delivery (VD) compared with cesarean section delivery (CSD) uniquely involves the pulsatile release of oxytocin from the posterior pituitary, uterine contractions and vagino-cervical stimulation. Oxytocin is a key mediator of maternal behavior in animals. Indeed, across experimental models including cesarean sectioned rats, goats and horses, vagino-cervical stimulation improves the acquisition of maternal behavior. This supports the notion that cesarean delivery, which deprives mothers of this stimulation and associated neurohormonal experiences, might decrease the responsiveness of the human maternal brain in the early postpartum."

The results are most significant in their possible implications for targeting candidate mothers for postpartum depression, as there may be a link between initial mother-child attachment and the depressive condition.

It is important to mention that the study only looked at short differences in brain pattern. As Tara-Parker Pope of the New York Times writes, "There’s no evidence that delivery method has any long-term implications on a woman’s ability to parent or bond with her child or recognize her baby’s cry."

It is also worth noting that the study was clearly limited by its size, only 12 mothers were tested. However, considering nearly 30% of births in the United States involve C-Sections further studies may be of interest.

http://www3.interscience.wiley.com/journal/121395695/abstract
http://well.blogs.nytimes.com/2008/09/05/delivery-method-affects-brain-response-to-babys-cry/

Tommy John Surgery

Tommy John surgery is the replacement of the ulnar collateral ligament with a tendon from the forearm or another place in the body. The procedure was first done in 1974 on Tommy John a pitcher of the Los Angeles Dodgers.

At the time of the injury the predicted chance of recovery was 1 in 100, now the chance of full recovery is anywhere between 85 and 90 percent. This procedure is commonly done on professional baseball players, most notably pitcher, due to the amount of stress on the ligament caused by the action of throwing a baseball. The procedure however, does not give one the ability to throw harder as it is commonly believed. This misconception has led patients to begin requesting the surgery hoping to enhance their performance. Doctors credit this phenomenon to the fact that pitchers who have the surgery become more focused on their conditioning and are in better shape after the surgery. They also explain it by the fact that the UCL degrades over time, and the surgery allows them to preform at the level before the ligament started to degrade. The surgery does not provide any better performance than what can be acheived with a healthy ligament.

This surgery has saved the careers of hundreds of baseball players since it has been preformed. Some, most notably Chris Carpenter, have come back better than they were before. I am impressed that this procedure, experimental 35 years ago, is not only a common place in the sports world, but a very successful one at that. With all the advances in medicine that have taken place over in 35 years time, its amazing that a better procedure has not been developed. I wonder with all advances and discoveries to be made in sports medicine if a procedure will be developed that will replace the Tommy John procedure.

http://www.usatoday.com/sports/baseball/2003-07-28-cover-tommy-john_x.htm
http://en.wikipedia.org/wiki/Tommy_John_surgery

vtpp 434-501

Alzheimer's, Parkinson's Diseases Could Be Halted By Protecting Neurons

Researchers at Southern Methodist University and the University of Texas at Dallas have identified some compounds that might slow the degeneration of neurons in aging patients, thus prolonging the onset of diseases such as Parkinson’s and Alzheimer’s.

These synthesized compounds are derivatives of compounds that have been shown to slow neuronal death, but are also toxic in doses not much larger than that which is protective so can not be used in humans. They are cell permeable chemical inhibitors of pro-apoptosic signaling molecules that have completely inhibited the death of cultured cerebellar granule and cortical neurons in tests. They have also prevented striatal degeneration and improved the behavioral performance of mice. These new compounds maintain the protective benefits of these older compounds such as GW5074, without becoming toxic at such low doses.

Currently, the only treatments available for these diseases are to treat the symptoms because the causes of diseases such as Parkinson’s are not well known. Therefore the patients have to take more and more drugs to try and sustain the same quality of life as more and more of their neurons die. This leads to unwanted negative side effects. If one of these substances or even some future approach proves to actually be able to stop the progression of the disease, the quality and ease of life could become exponentially better for these patients. So far these compounds have not been thoroughly tested, only in mice, but they do offer hope for a better future for elderly patients. As neural research continues, the chances that someday these diseases will actually be preventable give our younger generation further security of mind as well.

Source: Kim Cobb (SMU)

VTPP 434-501

Brian Bass

White Matter and You

Researchers at the University of Bonn are investigating a possible connection between the neural connections in our white matter and our personalities. A group of 20 subjects were given surveys to ascertain whether they tended to be more adventurous, extroverted novelty-seekers or more grounded, introverted comfort-seekers. The researchers then imaged the subject brains with diffusion tensor imaging, a form of MRI usually used in clinical studies to evaluate brain damage.

They found that the novelty seekers tended to have much more white matter connections between the hippocampus (which we learned in class is a major player in storing memories) and the ventral striatum, which has been identified as a planning and reward center. The comfort seekers tended to have more white matter connections between the ventral striatum and the frontal lobe, which plays a role in following societal norms (among many, many other things).

The research implies that the novelty seekers are neurologically more inclined to feel rewarded by trying new things and making new memories, while the comfort seekers are neurologically more inclined to feel more rewarded by old, familiar activities.

To this point, there have been very few studies in how white matter connectivity affects personality. This study is very interesting for many in the fields of neuropsychology and neurophysiology, as it is attempting to discern how personality is affected by the brain’s architecture.

Jeremy Rogers
VTPP 434-502

From:
Lauren Cahoon, “A Brain Circuit for Bungee Jumping?” ScienceNOW, November 24, 2008.
http://sciencenow.sciencemag.org/cgi/content/full/2008/1124/1

Robot and Its Biological Brain Could Offer Keys to Alzheimer’s, Parkinson’s

Researches in England are trying to determine how the brain learns and stores memories by using a biological brain to control a robot. Researchers at the University of Reading have announced that they developed a robot that is “controlled by a biological brain formed by cultured neurons that were allowed to grow, divide, and connect in a laboratory.” Scientists at the university are hoping that by watching the brain in action, how it stores and accesses memories, they will learn about diseases such as Alzheimer’s and Parkinson’s, as well as strokes and brain injuries. The rest of the article goes on to talk about other experiments using moths and monkey brains to control robots. This article is fascinating because it opens up a whole new realm of science that was previously untouched. By being able to study neurons in such a controlled and methodical manner, our knowledge of how the brain works will no doubt increase exponentially.

http://www.computerworld.com/action/article.do?command=viewArticleBasic&taxonomyName=Health_Care&articleId=9112631&taxonomyId=132&intsrc=kc_li_story

Nitric Oxidecan Can Change the Computational Ability of the Brain

I found this article interesting because we just learned about the way neurons and neurotransmitters work within the brain. At the University of Leicester they explored how Nitric Oxide affects the nerve cells. Nerve cells communicate using synapse. This is where chemicals are packaged into vesicles and released to the post synaptic neuron. This process is tightly controlled. Nitric oxide is a chemical messenger. It can diffuse across cell membranes, but it cannot be stored. “”IT is broadly localized in the CNS, where it influences synaptic transmission and contributes to learning and memory mechanisms.” It can be difficult to study because only small amounts are released at a time. They have created a “giant synapse” that is called the clayx of Held. It was developed at the University in the 19190s. They are now using it to study auditory pathway of Nitric oxide signaling in the brain. They were able to show that NO suppress a key potassium ion-channel in response to an incoming synaptic activity. NO shifts the activity of the ion-channels out of the normal. The electrical potentials are normal short, but when slowed by the NO information passage is reduced. They also found the “”whole population of neurons were affected” including neurons with no active synaptic input. This made the Nitric oxide a “volume transmitter” meaning that the NO could pass information between the cells without a need for a synapse. Although NO can be extremely toxic and can cause death of nerve cells, its functions can make communication for the brain easy. This signaling mechanism could be the be part of neurodegeneration left unchecked from pathologies of stroke and dementias. But in the Future the research is being continued and these mechanisms could lead treatment for Alzheimer’s Patients.
http://www.news-medical.net/?id=43499

Exercise Increases Brain Growth Factor And Receptors, Prevents Stem Cell Drop In Middle Age

Looking for that extra incentive to exercise more? Well look no further. According to researchers at the National Cheng Kung University Medical College in Taiwan, exercising may have a beneficial effect on neurogenesis, especially during middle age. Research suggests that exercise restores a brain chemical essential in the promoting the production of new stem cells.

As we have learned, the hippocampus plays an essential role in memory and learning. Inside the hippocampus, the body facilitates the division of neural stem cells and progenitors. Research has shown that a decrease in the production of these types of stem cells can result in impairment of the brain’s’ functions, such as learning and memory. The team of researchers built on earlier studies that the production of stem cells in the hippocampus drops off during middle age.

The researchers targeted two variables that may potentially cause this decrease in production: a rise in corticosterone or a fall in nerve growth (neurotrophic) factor. Their tests tracked mice at varying ages, some of which were subjected to exercise. By monitoring their neurogenesis, age, exercise, serum corticosterone levels and brain derived neurotrophic factor and its receptors, the team was able to find that exercise significantly reduces the loss of new nerve cells in middle aged mice.

They found that at middle age, stem cell numbers of the mice were 5% of what they were in the younger mice. Their findings also showed that the production of neural stem cells improved by about 200% for the mice subjected to exercise, and that survival and growth of these new stem cells improved by 170-190%. After conducting the research, it was evident that the drop in stem cell production was not due to a drop in corticosterone level, but due to an increase in the neurotrophic factor and its receptors. This article intrigued me with its idea that physical health plays an important role in our mental health, and that exercise not only helps keep our body in shape, but our mind and intellect as well.

Shawn Schepel
VTPP 434-502

Source:http://www.sciencedaily.com/releases/2008/11/081118071144.htm

A GENE FOR SPEED

Whether you're better suited to run a marathon or a 100-meter sprint correlates with a gene called ACTN3, researchers find.

The alpha-actinins are an ancient family of actin-binding proteins that play structural and regulatory roles in cytoskeletal organization and muscle contraction. alpha-actinin-3 is the most-highly specialized of the four mammalian alpha-actinins, with its expression restricted largely to fast glycolytic fibres in skeletal muscle. The gene encodes the protein [alpha]-actinin-3, which functions in the fast-twitch muscles. These muscles give the extra power needed for brief and vigorous bursts of activity, such as sprinting and speed skating.

Previous studies revealed that about one out of five white people in Australia has a variant of the ACTN3 gene that cannot yield [alpha]-actinin-3. Because people with the deficiency seem healthy, the protein appears to be unimportant for day-to-day activities. Most likely, it's significant only in the extremes of performance. That's where the athletic connection comes in. Researchers theorized that because the protein affects fast-muscle fibers, a deficiency of [alpha]-actinin-3 might be detrimental to speedy running and thus less likely to occur in elite sprinters. To test their theory, the researchers genetically screened a group of world-class athletes, including Australian Olympic competitors, and a control group of nonathletes. All the participants were white. The scientists divided the athletes into two groups: sprinters, which included speed skaters, and endurance athletes, such as marathon runners and rowers.

Of the sprinters, 6 percent had the gene variant leading to [alpha]-actinin-3 deficiency. That's one-third the rate for nonathletes, 18 percent of whom carried the variant. With a rate of 24 percent, endurance runners were similar to the nonathletes.
"The unique finding of this study is that the sprint athletes are different," comments Tuomo Rankinen of the Pennington Biomedical Research Center at Louisiana State University in Baton Rouge. "The endurance athletes do not really differ from the nonathletes in terms of this genetic marker."

There is, however, a gender difference. None of the female sprinters was [alpha]-actinin-3 deficient. Researchers think that in male sprinters lacking the protein, hormones such as testosterone may compensate for the protein deficiency.
Previous studies have shown ethnic differences. Some 25 percent of Asians are [alpha]-actinin-3 deficient, compared with only 1 percent of Bantu-speaking people in Africa. Researchers say that the importance of [alpha]-actinin-3 protein for athletic performance may vary in different human populations.
"We know that at the moment, the best sprinters in the world are black," researchers say. So, the next question for the researchers is to compare the frequency of these ACTN3 genotypes in black sprinters with [that of] the general African-American population, for example.

The reason why this blog is important to us is because it talks about the fast twitch muscles, one of the skeletal muscles that we studied about recently in the muscle physiology.

http://www.sciencecentric.com/news/article.php?q=07042401


Mithil Chokshi
VTPP 434 section 501

These Germans Cured AIDS

While treating a patient that had both leukemia and a complete case of AIDS, the physicians decided to try a little something different. They did a bone marrow transplant using blood stem cells from a donor that was immune to HIV. About 10 years ago, doctors discovered that a few of their male patients never contracted AIDS, despite engaging in risky sex with hundreds of partners. It was found that these people had a rare mutation called Delta 32 that blocks a molecule in HIV from adhering to the cell, an immunity. This mutation must be inherited from both parents and it occurs in around 1 percent of European populations. However, this mutation is pretty much unheard of in Africa and Asia. This made it difficult to find a donor in Germany, of course, but it was done.

The patient in question was asked to stop taking his antiretrovirus AIDS medication until after the transplant, when the virus levels in his bloodstream rose. To the doctors' surprise, however, no traces of HIV were found post-transplant. This was a cure for this particular man's AIDS.

Bone marrow transplants are extremely dangerous and painful. The procedure involves essentially wiping out the patient's immune system with chemotherapy and radiation. This brings with it a 30 percent mortality rate, so some people would prefer to stick to the antiretroviral meds. Finding a good donor with the Delta 32 mutation is not always possible and is usually patient specific. If the donated cells are not taken from someone with similar leukocyte antigens, then it is likely that the transplant will be rejected an cause a severe disease.

Over time, this procedure can be adapted and a better, safer path to curing those with AIDS may become clear. One thought, through refinement of genetic understanding and immunology, would be to take a "snipping" of DNA that codes for the Delta 32 mutation in the blood cells and transplant them into the patient, allowing their OWN cells correct the autoimmune deficiency. this would be a major push toward curing a myriad of problems, but such approaches are decades away.

Neuron Regeneration to be Restored

Unable to truly repair itself when neurons or axons are damaged, the adult nervous system is quite difficult to repair from the outside looking in. Spinal cord injuries are typically left uncured because of this difficulty and research behind regeneration of neurons has not been very promising. Until now, signaling molecules were not looked at but researchers have done studies with mice that show that certain compounds inhibit regeneration within the nervous system. Although only limited regrowth has been captured, "this is one of the most dramatic results in the history of the field," according to Ben Barres, a neurobiologist at Stanford University in California.

Because adult neurons are no longer as flexible, they do not exhibit regeneration abilities but this is not the focus of recent studies. Scientists are more focused on the compounds near the sites that prevent neuron regrowth. Deleting genes within mice that are involved in cell growth, scientists are studying the affect that gene manipulation has on the mice. The signaling molecule, PTEN, had dramatic results causing 50% of the neurons to survive and 10% to regrow when normally 80% of the damaged axons die.

The neurons have not yet been further tested for whether or not they function properly with working connections after regeneration but regrowth itself is already a breakthrough. The studies formulate around the idea that axon and neuron regeneration must be restored by preventing the inhibitory molecules.

"Coaxing Injured Nerves to Regrow"

http://sciencenow.sciencemag.org/cgi/content/full/2008/1106/1

Brittany Sanchez

VTPP 434-502

Light-wave implant for the hearing impaired

As we learned in class, different nerves can be stimulated by stimuluses that aren't intended for them. Similar to occular nerves producing random bright spots when exposed to pressure, auditory nerves can be stimulated with light. This is by no means an easy task, however.

Researchers at Northwestern University have found that shining light at a guinnea pig's auditory nerves produced a greater response at the relay between the inner ear and the brain (much better than cochlear implants).

The norm for implants for hearing impaired is a cochlear implant which can only stimulate around 20 out of over 3000 auditory sensors. This clearly means that hearing scope will be limited in sensitivity. But by using IR light, sensors can pinpoint better more of those auditory nerves. This will allow an individual to pick up different frequencies of sound over a broader range much better, giving them an overall better scope of hearing.

One of the most interesting things about this, and also most difficult things, is the idea behind converting one type of stimulus into another. Since the auditory range of the human body is quite large and complex, understanding how to essentially translate the language of light into the language of sound, and do so in a way that allows the body to understand this translation. Simple intensity increases probably won't be enough since auditory nerves sense both frequency and amplitude of a signal. Obviously this is a difficult task.

If researchers can just correlate light signals to a corresponding auditory signal, and ensure that the auditory nerves pick it up in the same way, the rest will be easy.

http://news.bbc.co.uk/2/hi/health/7737307.stm

I'll Have My Burger Petri-Dish Bred, With Extra Omega-3

How do you prefer your beef? Certified Angus, grass fed, or culled from a petri dish? That last option may be coming your way soon, courtesy of New Harvest, a loosely knit consortium of international scientists who are investigating an innovative new way of satisfying the world’s craving for meat. They plan to grow it in a lab—no animals required.

Lab-grown meat is “less unnatural than raising farm animals in intensive confinement systems, injecting them with synthetic hormones, and feeding them artificial diets made up of anti­biotics and animal wastes.” Known as in vitro or cultured meat, the end product, grown from stem cells, could alleviate environmental and health concerns associated with most animal protein (not to mention moral qualms about eating animals), making it the cut of choice.

To a certain extent, in vitro meat has already been produced hundreds of times in labs around the world, as stem cell researchers crank out bits of artificial muscle and connective tissue, hoping to mend weak hearts or reverse muscular dystrophy.

Currently, most research into lab-grown meat comes from biologists in the Netherlands. The Dutch government is funding the work. Henk Haagsman, one of the lead scientists on the Dutch project and a member of the New Harvest advisory board, says the key to making in vitro meat is to get stem cells to divide repeatedly, ultimately spawning billions of offspring; those daughter cells would then fuse and mature into a uniform, solid block. So far, Haagsman has created a small layer of fused meat cells—something akin to the world’s thinnest slice of bologna—grown from a single pig-muscle cell.



VTPP 434
Susan Vanderzyl

http://discovermagazine.com/2008/oct/22-i.ll-have-my-burger-petri-dish-bred

Brain implant allows mute man to speak

Scientists at Boston University in Massachusetts are working with a patient who has locked-in syndrome. It is a condition where the entire body is paralyzed. Patients with locked-in syndrome are only able to blink their eyes, but are fully conscience. They have implanted an electrode into the patient's brain to help synthesize vowel sounds. The researches believe that this could help similar patients produce whole sentences in the near future.

Frank Guenther and his team used fMRI(functional magnetic resonance imaging) to determine whether the man's brain could produce the same speech signals as a healthy person's. Once the device was implanted, the team used a computer model to decode the signals coming from the brain to help figure out which vowel sounds the patient was thinking about. "The long-term goal within five years is to have him use the speech brain–computer interface to produce words directly," Guenther says.

One positive aspect of this project is that the patient is more optimistic about life. He's really excited that he's able to try out this new technology that might one day allow him to communicate with his loved ones again. The next step is to train the computer to recognize consonant sounds so that the patient might one day be able to form complete words.


-Ricardo Raul Arteaga


http://www.nature.com/news/2008/081121/full/news.2008.1247.html?s=news_rss

Maintaining Concentration

Focus and concentration occur in the prefrontal cortex of your brain. This is where the high-order processing is done. The prefrontal cortex also controls the release of neurotransmitters, hormones, and other chemicals.

Dopamine is one of the “other chemicals” your prefrontal cortex controls. Dopamine affects behavior and cognition as well as motivation, attention and learning. It has been found that this “pleasure chemical” gives you a good feeling when the levels rise. It drives you to concentrate and motivates you to continue with your goal. As your dopamine levels drop, you lose concentration and begin to look for an alternative distraction.

Other factors also influence your level of concentration. Factors like stress, fatigue, anger, email and television can inhibit concentration. The major factors inhibiting concentration are lack of sleep, stress and anger. Inadequate sleep causes a deprivation of oxygen, which limits the release of neurotransmitters in the prefrontal cortex (dopamine and adrenaline). Stress and anger cause the release neurotransmitters norepinephrine and cortisol. This causes you to hyperfocus and inhibits concentration.

Researchers have found several methods to increase concentration span:

1. Sleep: getting a full night’s sleep will “reset” your brain and allows you to concentrate.
2. Snack: having a snack and a glass of water helps aid focus. It hydrates you and keeps your blood levels even.
3. Use more than one sense: using two of your senses sharpens concentration. For example, reading aloud may help you concentrate on the book you’re reading.
4. Start moving: aerobic exercise has been proven to increase concentration by activating dopamine in the brain.
5. Think about Happy Things: happiness reduces stress hormones that can impede concentration.

Invasion of the Body Snatchers

The sensation of walking in someone else's shoes has been taken one step further by scientists at the Karolinska Institute in Stockholm. Neuroscientists have created a "body-swap" illusion in a series of volunteers using simultaneous visual and motor stimulation from another's body. A headset covered the volunteers' eyes and displayed a 3-D view of the other person's perspective via a small camera next to their head. There were also tests done with a male mannequin as the "other person" and volunteers reported the same results. Both the mannequin and volunteer were poked in the stomach by a prod, giving them them the sensation that they were inside the body of the mannequin itself. They said that they had an expectation for the mannequin to move if their own bodies moved. However, they never reported feeling like plastic. 

The set of tests done with a female researcher instead of a mannequin were also very informative. Wearing the same visual headpiece, a volunteer would get a tingling sensation in their fingertips if they saw a knife being passed over the arm of the researcher. This sympathy reflex is more evidence that visual stimulation alone can cause false sensory reflexes. "In the body-swap illusion, we can see that multi-sensory information powerfully affects the brain," said neuroscientist Patrick Haggard, who was not on the research team. Another part of the experiment involved shaking hands with the mannequin while wearing the headpiece, giving volunteers the feeling that they were shaking hands with themselves.  

http://www.sciencenews.org/view/generic/id/38664/title/Your_body_is_mine

"Key Mechanism behind Cancer Spread is Explained"

Metastasis, which is the spread of cancer cells from one part of the body to another, is one of the leading causes of death from cancer and also one of the biggest challenges in the way of curing cancer. The more a cancer is metastasized, the more complicated and severe treatment for that cancer gets. Scientists at the Institute of Cancer Research have now discovered one of the leading causes of this metastasism.

Their research shows that competition between two proteins, "Rac" and "Rho", is directly responsible for cancer cells changing shape and spreading throughout the body. The hypothesis is based upon the fact that cancer cells come in different shapes, which have the ability to survive in different parts of the body. The proteins associated with the "Rac" activity cause the cell to become elongated, while the "Rho" activity causes the cell to take on a more round shape. Each activity attempts to surpress the other, giving the cancer cells more elasticity and a greater chance of survival in different places throughout the body. Previously, it was known that the cancer spread through cell shape transformation, but the cause of this transformation was still unknown. These results came from a study done on melanoma cancer cells, which are the cause of the most serious type of skin cancer. Knowing the cause of metastasis will help scientists develop therapies for preventing the spread of cancer in the future.

http://www.sciencedaily.com/releases/2008/10/081030194338.htm

Muscular dystrophy stem cell hope

Muscular dystrophy is a degenerative disease in which the muscles continuously weaken. It is caused by a genetic mutation that inhibits the production of the protein, dystrophin and the muscles to not regenerate once injured. Embryonic stem cells have been researched to be able to reproduce defective cells in the body due to their pluripotent nature. However, it has proven difficult to get the stem cells to develop into muscle cells, which is necessary in order to reverse the effects of muscular dystrophy. A recent study at University of Texas Southwestern determined that if you genetically manipulate the stem cells to release a vital chemical, they will develop into muscle cells. With this development, the many muscle-forming stem cells have a possible theraputic use. Then, the researchers delivered the drugs to the muscles either by injection straight to the muscle itself or intraveneously. They recorded significant improved muscle function. This is very exciting because this is the first time that this kind of treatment has been successful in animals. There is still a lot of research that needs to be done but in about a decade this could be possible in clinical trials. This is interesting because of our recent discussions on stem cell applications and the unlimited possibility of treatments using stem cells. It was also interesting because of our recent knowledge if muscle and their functions, and a presentation on muscular dystrophy. This research proves promising possiblities in the use of stem cells, but it is still very early in the development of these theraputic techniques, and in the next decade or so large improvements could be made in treatments for so many diseases.

Physical Therapy for Failing Hearts

Congestive Heart Failure is when the muscle in the heart deteriorates over time. When the muscle begins to deteriorate the heart isn't able to pump as efficient and as of now the only solution to this problem was a heart transplant . Almost 5 million people in the United States suffer from congestive heart failure, and 400,000 new cases are diagnosed each year.
The cause of this heart failure is still unknown, although it has been shown to appear more frequently after a heart attack.

When other areas of the body such as ligaments and muscle are damaged in an accident, they are able to heal over time and meet the demands that are placed on them. Dr. Criscione from Texas A&M believes that the heart may be able to heal over time just like other parts of the body do. When a person damages a ligament in their knee they go through physical thearapy and slowly work their way back to normal function. When the heart is damaged it is a little more complicated because there is a constant load applied on the heart so it doesn't have time to heal as efficiently.

Dr. Criscione believes he may have a found a solution to this problem. Criscione has came up with an invention called a direct cardiac compression device. This device is implanted around the heart like a flexible cup with hollow walls. Pumping air into the walls of the cup squeezes the heart and pushes blood out. Letting the air out allows the heart to expand and fill with blood. This device can help ease the load on the heart over a period of time and possibly allow the heart to completely regain it's function and efficiency.

Criscione conducted 18 months of long-term efficacy trials in sheep, studying the heart’s performance during the time the device was implanted. The results of Criscione trials showed that there was improvement in the hearts efficiencny and normal motion of the heart was restored.


http://engineering.tamu.edu/research/magazine/2006/heart/
http://www.americanheart.org/downloadable/heart/1192042694547Criscione.pdf


Patrick Long
VTPP 434 Section 502

The Promise and Power of RNA

Pharmaceutical companies are focusing more on RNA than the "protein-making genes." Recent scientific discoveries show that RNA has more of an impact on the actual protein than a gene that can code for many proteins (as we learned in class). When the strand of DNA transcribed a strand of RNA, the RNA has some control over the protein that is created.

“This is potentially the biggest change in our understanding of biology since the discovery of the double helix,” said John S. Mattick, a professor of molecular biology at the University of Queensland in Australia.

Pharmaceutical companies have developed a drug called RNA Interface, or RNAi. They are creating drugs that are stop the production of a protein, instead of trying to repair the damage caused by a protein that was already produced.

The two scientists credited with discovering the basic mechanism of RNA interference won the Nobel Prize in Physiology or Medicine in 2006, only eight years after publishing their seminal paper. And three scientists credited with discovering the closely related micro-RNA in the 1990s won Lasker Awards for medical research this year.

Research is focusing on micro-RNA, short strands of interference RNA that can reduce protein production. So far, more than 400 strands of micro-RNA's have been found. Since each strand has the possibility to affect hundreds of genes, "the activity of more than half the genes in the human genome is affected by micro-RNA," according to David P. Bartel, a biologist at the Whitehead Institute in Cambridge, Mass., and at the Massachusetts Institute of Technology.Scientists have discovered that micro-RNA's contribute to the formation of some cancers, the ability to block cancer, and the proper function of the heart and blood cells.

Other types of RNA have also been discovered, including small interfering RNA (siRNA), piwi-interacting RNAs (piRNA), chimeric RNA, and promoter-associated and termini- associated long and short RNAs. PRe-existing RNA include messenger RNA (mRNA), transfer RNA (tRNA), and small nucleolar RNA (snoRNA), which all play roles in protein production. Although scientists do not understand what each type of RNA does, they allow for a lot of future options to cure and treat protein related diseases. Not is the function of the RNA types unknown, scientists also disagree about their actual function. Some believe that RNA has the ability to turn on and off genes, while other scientists think that RNA can only fine tune the genes and increase or decrease the prominence.

All of the new discoveries are “revealing a level of regulation and complexity that I don’t think the current organizational model of the genome ever envisioned,” said Thomas R. Gingeras, professor and head of functional genomics at Cold Spring Harbor Laboratory.

Currently, scientists are focusing on interference RNA. While in theory it is easy to understand how interfering RNA could silence a gene, there is no convincing data that it will work in humans. There is also the fear that the RNA could might silence genes beyond its intended target, which would cause unwanted effects. Scientists plan to use double-stranded RNA, however, it does not actually occur in the human body. When trying to get into a cell, it sets off an immunoresponse because the body recognizes the double stranded RNA to be a virus. Also, most cell membranes are negatively charged, as is the RNA. So, the RNA would never hit the cell. Many startup pharmaceutical companies are researching entry methods.

Another pitfall of RNA interference is that it only turns genes off and cannot stimulate the cell to increase protein levels. However, it was discovered that RNA activation can. RNAa can cause a gene to become more active and enhances the activity of proteins to bind to the gene promoters.

While no treatments have been created as of yet, there is research being done on this new potential treatment to many disease.



http://www.nytimes.com/2008/11/11/science/11rna.html?partner=permalink&exprod=permalink

Neuroimaging Reveals Who Said What

What if someone could read your mind? Or more specifically, look at your brain and decipher who spoke to you and what was said? In an article found in Science, researchers worked with neuroimaging to map brain activity in response to sounds and voices. They stated that voices can be recognized by unique neural fingerprints in the brain of the listener. Eventually, advances in this area could improve computer systems for automatic speech and speaker recognition.

The vowel sounds of a, i , and u were spoken by three different people to seven volunteers. Functional MRI (fMRI) measured brain activity of the test subjects and an algorithm was developed in order to interpret the activity into relationships that could determine identity of the voice. It was concluded that certain acoustic characteristics of vocal cord vibrations or neural patterns, which are unique and specific, determined brain activity. The neural fingerprints did not change even if the speaker said something else.

Their research also found that areas of the brain just thought to be linked to early stages of sound processing also took part in complex sound decoding. It was previously assumed that after the brain processed simple speech sounds, it then analyzed the sounds into words in very specialized areas. After this study was conducted, it was revealed that speech processing is more evenly spread out across the brain.

This study foreshadows the possibilities that can unfold with more understanding and mapping of the brain, which is especially thrilling for bioengineers.

NWO (Netherlands Organization for Scientific Research) (2008, November 10). Neuroimaging Of Brain Shows Who Spoke To A Person And What Was Said. ScienceDaily. Retrieved November 11, 2008, from http://www.sciencedaily.com­ /releases/2008/11/081110071240.htm