Wednesday, March 31, 2010

Reverse Epidemiolgy

Reverse epidemiolgy according go Wikipedia is "a term for a medical hypothesis which holds that obesity and high cholesterol may, counterintuitively, be protective and associated with greater survival than certain groups of people." This would be like saying, people with class I obesity with heart disease do not have a greater risk than people of normal weight who also have heart disease.

Dr Kamyar Kalantar-Zadeh, MD, PhD is leading a group of researches at the University of California on this contoversial theory. They are also comparing their studies with dialysis patients. For many years poor survival rates in dialysis patients were based on the presence of traditional CVD risk factors (high blood pressure and obesity). Studies they have been doing, however, have actually failed to show this. Some of their research showed that high BMI and high serum albumin and lipid levels are consistently associated with better survival.

Most of their studies have been observational, but a few have been interventional. For instance, one in Germany done a couple years ago showed that dialysis patients who took statins received no survival benefit at four years' follow up compared with patients who received placebos. Dr Kalantar continued on speaking on about patients and their ability for transplants, and how these patients should be cared for (lower BP? loose weight??).

I found this article interesting because this is something we normally don't think about. We always associate obesity and high blood pressure as two bad and harmful things to our bodies. There is more being done in this study comparing their ability for transplants, etc. and should definitely get some attention.

Eva Szabuniewicz
VTPP 435-501

http://www.renalandurologynews.com/reverse-epidemiology-dialysis-paradox/article/20532/

Injection of Gold Nanoparticles may open new way to treat tumors and Cancer

“Nanoembolization” is a procedure that loads tiny gold nanoparticles with a cancer killing agent. These nanoparticles, constructed by northwester researchers, measure 13 nanomenters in diameter. This technique allows researchers to inject the cancer killing agent directly into the tumor. By doing this, the nanoparticles are more than fifty times more concentrated within the tumor than traditional treatments.
This new finding can cause huge improvement in the most deadly types of cancers, such as pancreatic. Specifically with pancreatic cancer, there are difficulties with getting the treatment to the area of the cancer. Scar tissue tends to build up and block the cancer-killing drugs from reaching the tumor preventing it from being of any use. Using the nanoparticles instead of traditional treatments allows the physician to insert the particles and drug through a catheter directly to the tumor. (The catheter is placed into an artery usually near the groin and navigated through blood vessels toward the site.) On top of this method having the potential to be more successful, it does not require surgery.
This method is both noninvasive, and prevents the scar tissue build-up from becoming too much of an issue. The cancer killing drug is able to end up where it is ended to. I found this article interesting because we learned some about gold nanoparticles and it shows the diverse range of expertise it takes to create new finds in medicine. Cancer is a disease that effects numerous people, and this new method of drug delivery could be effective for the most deadly types of cancer. This has the potential to save money, hassle, and lives.

http://www.prnewswire.com/news-releases/going-for-gold-with-a-novel-interventional-radiology-treatment-for-pancreatic-cancer-87781397.html

Erica Williams
VTPP 43-502

Contacts that can monitor glaucoma

Glaucoma is a serious condition. It is a condition that usually associated with high pressure building in the eye. The main issue with treating the condition is the constant changing pressure in the eyes making treatment difficult. The only way for a doctor to properly treat this condition properly would be constant observation. A new set of contacts can fix this by being able to monitor pressure in the eyes. It is a silicon hydrogel with sensors and a microprocessor. It can transmit the data wirelessly to a receiver around the neck. It has a strain gauge that causes the diameter of the cornea to change. Using the tracked data doctors can come up with a more effective treatment or the find out the viability of options like surgery. The contact lens offers options that were not previously not available to most doctors to manage glaucoma and possibly other diseases.
http://www.popsci.com/science/article/2010-03/sensor-equipped-contact-lens-monitors-glaucoma-symptoms-around-clock

"Smart Coating"

There is a new “smart coating” that contains nanosilver particles. This coating helps implants adhere closer to bone and protect against infection. Some patients that have replacement surgery, their body will reject the implant. The “smart coating” helps address this problem by allowing the bone to grow into the implant without breaking the bone. “The coating creates a crystalline layer next to the implant and a mostly amorphous outer layer that touches the surrounding bone”. The outer layer dissolves over time. When the outer layer dissolves, it releases calcium and phosphate. This helps encourage bone growth. The bone will grow into the implant as the outer layer touching the bone dissolves. This will result in enhanced bonding between the implant and the bone. The “smart coating” also helps make the implant more functional because the implant and the bone will share the load equally.

They can also change the rate that the outer layer dissolves. They want this rate to equal the rate of the patient’s bone growth. This is imperative because different people will have different bone growth rates. For example, a younger person’s bones will grow a lot quicker than an elderly person.

The silver nanoparticles in the “smart coating” are “antimicrobial” as the outer layer dissolves. With the “smart coating”, patients will not have to take a large quantity of antibiotics to help prevent infection from occurring right after surgery. The silver nanoparticles will also help prevent infection at the location of the implant for as long as the implant is used. This is significant because after normal implantation, the location of the implant will constantly be susceptible to infection. There is a higher chance of infection occurring right after surgery. Therefore, more silver is secreted right after surgery. This is because of the outer layer dissolving faster. When the patient is healing, the silver secretion slows down.

This smart coating is bioactive because it is a material that forces a tissue response. The researchers understand what triggers the cells to react as they would like. The researchers also know what activity they are trying to encourage. These are all important characteristics for a material to be considered bioactive. This smart coating will help patients in the future to have safer hip, knee, and dental implants. I find this topic very interesting because inventions like “smart coating” will help change people’s lives using biomedical engineering.


http://www.devicelink.com/mpmn/blog/?p=3517

Cycling Provides a Break For Some With Parkinson’s

Parkinson’s disease is a disorder of the central nervous system; it is considered a movement disorder that impairs motor skills. Some of the symptoms include: tremors, muscle rigidity, slowing or loss of the ability to physically move. This is both a chronic and progressive disease, meaning that it cannot be cured and that it worsens over time. Since PD is a neurological disorder, the cause is damage to the brain, including the death of specific brain cells that cause movement.
Recently, it was found that cycling may be a plausible way for patients with this debilitating disease to exercise efficiently while doing a normal everyday activity, improving their quality of life. Some patients that have even lost the ability to walk are able to ride miles on their bicycles, freeing them from the confines of their disorder. It is also believed that regular exercise slows the progression of the disease, which is also important, since there is no cure.
Doctors are unable to explain at this point how these severely affected patients that are unable to walk can ride their bikes in such a remarkable way. One explanation is that PD may not affect the part of the brain that involves riding a bike or the rhythmic movement of the pedals allowing the nervous system to conduct a cycling movement. Although all of the symptoms return when the patient gets off of the bike, it still provides an excellent cardiovascular workout for people that may otherwise be unable to exercise.
I am particularly interested in this article because my dad is an avid cyclist. Although he does not have Parkinson’s disease, I found it very interesting that the sport he loves so much is one that is able to help patients that have trouble even walking to exercise normally.

link to article: http://www.nytimes.com/2010/04/01/health/01parkinsons.html?ref=health

Charlcie Northrop
VTPP435-502

The Scourge that is ‘Man Flu’

In a study conducted by Dr Olivier Restif, a Royal Society University Research Fellow, and Professor William Amos at the University of Cambridge, a mathematical model was developed seeking to answer the question as to why men appear to be more prone to illness than women.

Prior studies indicate that not only are men at higher risk for infection, but that their illnesses are more severe and lingering. However, this apparent fact seems paradoxical in terms of evolutionary development because if men are more often exposed to disease than women (a generalization) shouldn’t they have developed a stronger immune system over time? Restif and Amos’ mathematical model incorporated many factors to quantify the male/female dynamic relationship between host and pathogen including: hormonal differences, extent of risk-taking behavior, bacterial/viral presence, and a key consideration often overlooked; the costs/benefits of immunity.

The study’s results indicate that the more adventurous lifestyles of males leads to greater exposure to infection, yet this also leads to lower immune protection. It is common knowledge that the human body adapts to handle external stimuli be it positive or negative, and Restif and Amos’ do not challenge this fact; instead they conclude that “above a certain level of exposure…the benefit of rapid recovery in males decreases owing to constant reinfection”. In other words, despite ridding oneself of infection at one point, the constant bombardment of pathogens males face due to their nature causes them to quickly become infected again. This ultimately means the benefit of evolving a stronger immunity isn’t worth the cost for males (a waste of time and effort). Hence, the genetic laziness of men has lead to observation that males have a weaker resistance to pathogens today; in retrospect this probably should have been more obvious since everyone knows men are ingrained with a ‘why bother’ attitude.

Furthermore, Restif and Amos stated that though their model only addresses diseases that transfer directly between hosts, the framework could be modified to pattern “sexually transmitted diseases and ‘vertical transmission’ from mother to offspring”, and similarly for a variety of future studies.

The method presented by Restif and Amos is important because it has the potential to provide extensive and novel understanding as to not only how but why viruses disseminate.

http://www.medicalnewstoday.com/articles/183485.php

A new outlook for prosthetics

The prosthetics limb world is being revolutionized, with one of the newest inventions coming from a 20 year old college student. Jonathan Naber, a student from the University of Illinois Champaign-Urbana has developed a prosthetic arm aimed for usage by people in third world countries who were previously unable to afford prosthetic limbs. Prosthetic limbs in the U.S. can cost around $10,000; Naber’s invention will be available for around $30.00. Naber invented a prosthetic arm which is made solely out of recyclable materials. His idea is to be able to mass produce parts which will be pre-assembled and put into kits with simple instructions of how to put together and attach the limbs. His invention does not use a prosthetic socket, as prosthetic arms always have. It fits to the body in a completely different way. I think it is so amazing that we are engineering new techniques for prosthetics in a way that makes them available to people who need them, but would otherwise not be able to afford them. It is also really neat that we are able to use all recyclable materials in our prosthetics today.

http://suburbanjournals.stltoday.com/articles/2010/03/31/monroe/special_feature/0331cla-naber0.txt

Magnetic field can alter moral judgments

Neuroscientists at Massachusetts Institute of Technology are discovering the effects of manipulating the right temporo-parietal junction of the brain. This is located on the surface of the brain behind and above the right ear. It is believed that this portion of the brain contributes to a person's morality. Especially when making moral judgments of another person's intensions.

The experiments involved using a magnetic field to alter the TPJ. The technique for this is non-invasive and is called transcranial magnetic stimulation (TMC). The magnetic field prevents the nerves in that specific area from firing in a normal manner. This effects the subjects only temporarily. Once they have been exposed to the magnetic field, they take an exam with different scenarios. They are told to judge the actions by the person in the scenario 1 (completely immoral) to 7 (morally acceptable). More people that underwent TMC judged unsuccessful attempts to harm someone as morally permissible.

It is surprising that a high-level behavior like morality can be altered by disrupting only a small part of the brain. Maybe scientists can analyze this new discovery on citizens incarcerated because of moral defectiveness.

http://www.scienceagogo.com/news/20100229220339data_trunc_sys.shtml

Risk-Taking Peaks In Adolescence, Male Study

A few researchers have come up with another discovery as to why adolescence seem to be willing to take more risks than the other age groups. In an investigation in the UK at the University College London, it was studied that teenage boys are most likely to take the risk because they find it thrilling. Lead author Dr. Stephanie Burnett stated that this seems like a "..one step forward in determining why teenagers engage in extremely risky behaviors such as drug use and unsafe sex." Her statement seems very true in the facts that younger aged adults make unweighted decisions off of run-in-the-moment instances. In this study, 86 boys and men with ages ranging from 9 to 35 played a computer game based on gambling and had to make decisions which were rewarded with points if the decision was a winner. It was also asked after if the decision was satisfying or dissatisfying. Emotional ratings did not differ with age. The main sign was that between childhood and adolescence showed a difference in relief and regret emotions. A u-shaped pattern that peaked at 14.4 years of age showed the pattern for risk seeking. It was also shown that teenagers had an increase enjoyment in a lucky escape. Development of this study is to be continued, and Dr. Sarah-Jayne Blakemore stated " Understanding why adolescents take such risks is important for public health interventions and for families".

http://www.medicalnewstoday.com/articles/184020.php

Schizophrenia and Estrogen

A new drug that influences the amount of estrogen in the brain is showing signs of improving the conditions in female schizophrenia patients. Specifically, it alters the neurotransmitter and neuronal systems in the brain. The drug is called Raloxifene, which has been previously used to treat osteoporosis, and has had successful tests on improving the conditions and quickening the recovery of women that develop postmenopausal schizophrenia. This new drug has not been proven to yield the nasty side effects, on the breast, uterus, and ovarian tissue, that the normal pills called estradiol do.


Professor Jayashri Kulkarni, the
research project leader and Director of the Monash Alfred Psychiatry Research Centre (MAPrc)
, gave the women in the trial 120mg of the estrogen receptor modulator a day. This dosage proved to yield better results than those given a lower dosage or a placebo. He stated, "many patients in this study had longstanding, persistent schizophrenia, so we are delighted that they experienced improvements in their mental well-being. We will continue to investigate the efficacy of Raloxifene which is a currently available treatment for osteoporosis in postmenopausal women.:


These tests have been performed with a small sample size so in order to further validate these findings more tests will have to be done. Kulkarni is quite optimistic that this drug could revolutionize the treatment of women with schizophrenia. He also hopes to carry over his tests to younger women and even men.



This article caught my interest because anything that has to deal with diseases of the mind spark my interest. I find schizophrenia to be quite fascinating and hope to learn more about it.


http://www.sciencedaily.com/releases/2010/03/100330092811.htm

-Charles Brown

For a lucky few, ‘dioxins’ might be heart healthy

Dioxins and dioxin-like compounds have long been considered toxic compounds. All people have receptors on their cells that respond to the presence of these compounds (and no other known compounds). So, for many years, it has been assumed that this receptor has no beneficial role. The problem observed in people exposed to dioxins is hypotension. Cardiologist, Lars Lind, immediately assumed that the dioxins must interfere with the body’s mechanism for allowing the blood vessels to dilate to reduce blood pressure. After making his hypothesis, he found a select group of people with a mutated dioxin-receptor gene. He found that when he injected people with a dioxin-like chemical, people with a “normal” receptor, the vessels constricted and blood pressure rose. In people with the mutant gene, initially, the vessels constricted and blood pressure rose, but quickly thereafter, the vessels dilated and blood pressure dropped. Therefore, this mutated gene may have benefits for the heart. Also, it was noted that the mutated gene is located on a segment of DNA that does not code for a protein.

I find this interesting because it serves as a good reminder of how little we actually understand about how we work. The more we understand about our own genome, the better we will be able to manipulate it, and I find the potential of gene therapy fascinating.

http://www.sciencenews.org/view/generic/id/57114/title/Science_%2B_the_Public__For_a_lucky_few%2C_%E2%80%98dioxins%E2%80%99_might_be_heart_healthy

The Risks of an Expanded Use of Crestor

The article I chose is about the controversy surrounding the new FDA approved use of Crestor as a preventative medication for people with low risks of heart attacks and strokes. Although statins like Crestor have been proven to be effective in saving lives, critics question if taking Crestor as a preventative measure is necessary, or even safe, for healthy people. New evidence shows that statins may increase the chances of developing Type 2 diabetes by 9 percent. Additionally, the blood test used to identify new statin candidates is controversial. This test looks for high levels of inflammation in the body, and doctors disagree whether this is actually related to cardiovascular problems.

Under the new FDA criteria, an additional 6.5 million people will be approved for Crestor, with 80 million people already taking it for cholesterol problems. The new criteria require that the patient be at least 50 if male and at least 60 if female, have high inflammation levels, and possess one other risk factor. The side effects can include muscle aches and high liver enzyme levels, which doctors have previously said are outweighed by Crestor’s ability to lower cholesterol. However, regardless of the new possible link to Type 2 diabetes, the FDA is approving the drug, which “showed a small, but measurable reduction of strokes, heart attacks, and other ‘cardiovascular events’ among people taking the statin, compared with patients taking the placebo.”

The trial the FDA looked at to approve this new use of Crestor only used patients with low cholesterol levels and high inflammation as measured by a CRP (C-reactive Protein) test. Dr. Paul M. Rider, the inventor of the test, was the one who convinced Crestor’s maker AstraZeneca to pay for the statin study. He also receives royalties from CRP tests. As the study found reductions in heart attacks, strokes, and angioplasty bypass surgery, the study was stopped after 1.9 years instead of the original five. However, critics still say that doctors and patients may have been misled because the patients in the study were already healthy.

By analyzing the statistics, it was found that Crestor only prevented heart attacks in 2 out of 1,000 in this group of people. This means that 500 people would need to be treated in order to prevent one heart attack, making AstraZeneca $638,000 in the meantime. Additionally, though statistically significant, it is not clinically significant. The bottom line is that, though the FDA has ruled that the benefits are worth the cost, there are still plenty of critics who disagree.

I liked this article because it showed some interesting points about the medical industry. The first is that there is plenty of disagreement within the medical community. As the article presented, there are many arguments for and against the use of Crestor as a preventative medicine. Additionally, it shows that even FDA approved medications come with risks. One needs to weigh both the costs and the benefits before one decides to start taking a particular medication. Finally, the article hinted at the fact that money played a part into the study that was done and in the future effects of the FDA’s decision. It shows that business, unfortunately, plays a role in even medicine.

http://www.nytimes.com/2010/03/31/business/31statins.html?pagewanted=2&ref=health

-- Nicole Wanlass, VTPP 435-502

Pacemaker in Stomach Helps Against Vomiting

Gastric electrical stimulation has previously been shown to be effective in most diabetics who suffer from severe vomiting due to the disease. New research shows that people with other severe stomach disorders could also benefit from this treatment.
27 patients were included in a study testing electrical stimulation of the stomach. 22 had fewer symptoms as a result of initial temporary stimulation, and 20 of these then had a permanent pacemaker surgically inserted into the stomach. Of the patients who responded well to temporary stimulation, 90% also had good results in a long-term follow-up of the surgically inserted pacemaker. The treatment led to reduced nausea and vomiting. In another study of 16 patients, electrical stimulation led to fewer days in hospital in the year following treatment.
Simple temporary stimulation through the skin can be used to identify the patients who could benefit from the treatment.
"We insert gastric electrodes into the patient under local anaesthesia through a small incision in the skin, and these are then connected to an external pacemaker," explains junior doctor Stina Andersson, a doctoral student at the Department of Internal Medicine. "If the results are positive, we can be relatively certain that treatment with a surgically inserted pacemaker will work for that patient. The next step is to insert a pacemaker using keyhole surgery."
Based on these studies and previous research, gastric electrical stimulation does not seem to affect the stomach locally.
"We believe instead that the stimulation somehow acts on the brain's centre for nausea and vomiting by activating the neural pathways running from the stomach to the brain," says Andersson.
Some diabetics with severe symptoms are already being treated clinically with a gastric pacemaker. Other patients with hard-to-treat gastrointestinal disorders could also now receive the treatment following careful examination and successful temporary stimulation of the stomach.
"The treatment could, for example, work on intractable nausea following chemotherapy or extreme nausea during pregnancy," says Andersson. "No studies have yet been performed in these areas, however."

http://www.sciencedaily.com/releases/2010/03/100329093619.htm

I found this article rather interesting because it relates directly with the class lectures right now. Adding a pacemaker in the stomach will regulate the action potentials which can reduce common vomiting and other complications.

Study shows mutation in 1 gene cause many cancers

A new study by scientists at the Ohio State Comprehensive Cancer Center- Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC- James) showed that a mutation in 1 gene showed a link between the development and severity of certain types of cancers. The mutation of the gene, called PTEN, can be passed to a child from the mother causing Cowden syndrome. This syndrome has already been linked to high cancer risk and high cancer severity of multiple organs in the body. The reason people with Cowden syndrome vary so significantly with cancer is unknown, but "[t]he animal study, however, linked specific mutations in the gene to distinct kinds of cancer in organs targeted by the syndrome." It was shown that in people with Cowden syndrome the mutation of the gene actually helped progress the cancer in those effected organs. The mutation of PTEN can also occur in normal body cells leading scientists to believe even further the link between cancer and the gene mutation. I think this article is significant because it shows how powerful your genetics are in your development and future. The mutation of one gene can lead to the catastrophic take down of the entire body. It amazes me how fragile, yet durable our human system actually is.

article: www.breakthroughdigest.com/medical-news/study-shows-that-mutations-in-1-gene-cause-many-cancers/

Tissue Regeneration Discovery

Researcher Ellen Heber-Katz once studied autoimmunity in mice to model lupus however; a small observation in these mice caused her to switch to study in autoimmune disease and transplant rejection. In the original research, mice, with and without lupus, had holes poked into their ears for identification purposes. However, the holes in the mice with lupus would keep closing to heal with little or no scarring which is not a normal response.

Cells from lupus and normal mice were compared and it was found that the lupus mice had “healer” cells which could be dedifferentiated. Dedifferentiation means that matured cells become more like immature undifferentiated cells that are not of a specified type. These cells were also multinucleated, which is commonly seen in cells that are about to divide, and they expressed many stem cell markers. There was one thing these healer cells did not express, the p21 gene.

Suppressing the p21 gene along with its regulator, p53 which is a tumor suppressor, causes an increase in the production of induced pluripotent stem cells, matured cells that are reprogrammed to behave like a stem cell. The suppression of p21 allows for the enhancement of healing and regenerating tissue. Current ways of regenerating tissue are done by culturing stem cells on a synthetic scaffold using chemicals outside of the body.

I found this article to be very interesting because this discovery can be utilized in the future for many medical applications. For instance, a patient who needs extensive surgery can heal a lot faster and with less scarring. Also, we could maybe find a way to suppress this gene with medicine so that new tissues can be grown in the body instead of outside which is the current method.

This article can be found at:
http://www.scientificamerican.com/article.cfm?id=case-closed-wound-healing

Kelsey Smegner
VTPP 435-501

Tuesday, March 30, 2010

Nibble on Chocolate for a Healthier Heart

By: Jennifer Warner
Recent research shows that eating a small piece of chocolate everyday can reduce your risk of stroke and heart attack. Researchers in Germany say that eating one square of a 100g bar everyday will reduce your risk up to 39%. However, they warn that eating too much can contribute to gaining weight. A study published in the European Heart Journal followed 19,357 adults for 10 years to observe how many times they ate a 50g bar of chocolate. By the end of this study the researchers found that the people who ate an average of 7.5g per day had a 27% lower risk of a heart attack and a 48% lower risk of a stroke than the people who ate an average of 1.7g per day. This group of people also had lower blood pressure than the group who ate less chocolate.

Researchers say that the benefit of chocolate is because of the high flavanol content of cocoa. Flavanol is an antioxidant that is more apparent in darker chocolate. Flavanols are responsible for the availability of nitric oxide, which causes smooth muscle cells of the blood vessels to dilate and lower blood pressure. Nitric oxide also contributes to improving platelet function which makes blood less sticky.

http://www.webmd.com/heart/news/20100330/nibble-on-chocolate-for-healthier-heart

Kelli Martinez
VTPP 435-501

Touch Bionics - The Next Generation of Artificial Hands

As of July 2007, Touch Bionics - a Scottish prosthetics company - has made its i-LIMB hand and Prodigits partial hand available to hand amputees across the US and Europe. The i-LIMB hand contains all five digits and is used as a total hand replacement. The Prodigits partial hand is used for patients who have lost one or more digits but not the entire hand.

Within these devices are two electrodes which contact the skin of the forearm and are used to pick up electrical impulses from the muscles of the forearm. A control software (which is integrated into the hand) is then used to amplify and filter the impulses in order to produce the appropriate signal needed to set the motor speed for each of the device's motors. Each digit in these devices is controlled by a separate motor, which allows for a wide range of motion. The thumbs of these devices can also be rotated manually, allowing the thumb to touch different fingers when the hand contracts.

The fingertips of these devices are specially designed in order to curve around an object when the hand contracts, providing for a solid grip. However, when the hand is contracting and the device senses that a finger has stopped moving (because it has grasped the object), a specialized control system determines the point at which the finger has achieved sufficient grip and then stops the finger from contracting any further. The motor for that finger is then locked until the user sends an "open" signal. This feature allows the user to maintain a solid grip on an object without crushing it.

The devices are modular in design, and thus damaged parts can be easily interchanged or replaced. The devices are also covered with a flexible material known as cosmesis which simulates skin and protects the device from dust and water damage. Cosmesis is naturally somewhat transparent, but can be detailed and stained in order to achieve an incredibly life-like appearance.

I found this article fascinating because these recent advancements in biotechnology have allowed hand amputees to once again have full use of both hands.

The article can be found at http://www.emeraldinsight.com.lib-ezproxy.tamu.edu:2048/Insight/ViewContentServlet?contentType=Article&Filename=Published/EmeraldFullTextArticle/Articles/0490350401.html.

Dangerous Custodians: Immune Cells as Possible Nerve-Cell Killers in Alzheimer's Disease

It is estimated that approximately 18 million people currently suffer from Alzheimer's Disease worldwide, and the number is rising. This form of progressive dementia is due to a loss of nerve cells from the brain that is associated with the formation of insoluble protein aggregates, called beta-amyloid plagues and tangles. It has been thought that Alzheimer's Disease occurs when large numbers of microgilas gather in the vicinity of the beta-amyloid plagues and degrade the plague.

Recently a discovery by an international team under the leadership of LMU neuroscientist Professor Jochen Herms found that microgila may actually make a significant contribution to the loss of neurons associated to Alzheimer's Disease by congregrating near stressed nerve cells. Stressed nerve cells release a signal that attracts microgila. Microgilia are the cells that are responsible for the immune response inside the brain and they start a protective inflammatory response to tissue damage and infection. When the microgila causes an inflammatory response, the result can be the destruction of the neurons in the area where microgila congregate.

An experiment was done on genetically modified mice that develop many of the symptoms of Alzheimer's Disease in humans. The mice were also engineered to make fluorescent forms of proteins that are specific for neurons and microgila, and the imaging technique enabled researchers to monitor the fate of identifable neurons and microgila over periods of weeks and months. This approach made it possible for the first time to visualize the loss of nerve cells in the brains of living mice. Nerve loss was found to precede the activitation of microgila.

This discovery shows that chemical signalling between microgila and nerve cells plays a crucial role in mediating neuron loss during the course of the disease. One of the most important aspects of the discovery was announced when Professor Jochen Herms said, "The possible chemical that causes microgila to go to stressed nerve cells may be the chemokine fractalikine, which docks onto a receptor protein on the surface of the microgila cells."

I found this interesting because my great-grandmother was diagnosed with Alzheimer's Disease. Alzheimer's Disease is a terrible disease that doesn't have a cure and any discovery that may lead to the cure for Alzheimer's Disease is interesting to me. This discovery could lead to possibily manipulating the chemical signals and reducing the communication between microgila cells and stressed nerve cells by disrupting the synthesis of chemokine fractalikine or rendering it ineffective by not allowing chemokine fractalikine to bind to the receptor protein on the surface of the microgila cells.

This article can be found at

http://www.sciencedaily.com/releases/2010/03/100322083855.htm

RNA Nanobots Combat Cancer

While nanobots largely remain in a developmental stage, scientists have been able to coax polymers on a nanomolecular scale to serve as vectors for specific drug therapies. Researchers at the California Institute of Technology in Pasadena have loaded RNA into polymer vesicles that are coated with the protein transferrin. This protein is attracted to the receptors on a variety of tumors. Upon contact between the vesicle and a tumor cell, the outer protein induces the cell to accept the contents of the vesicle. Once the particles are inside the cell, the environment within the cell triggers the disassembly of the particles and the release of RNA interference. These RNA molecules inhibit the action of a gene that makes a growth protein called ribonucleotide reductase, commonly found in cancer cells.

The treatment is administered via four intravenous injections of RNA-loaded nanoparticles, typically lasting about thirty minutes per injection, over the course of three weeks. The recent conclusion of a trial involving three patients with melanomas bodes well. Samples taken from the melanomas after the treatment show the presence of RNA interference and the reduction of cancerous gene expression. Gene therapy via nanobots is a promising area in the field of medicine as the manipulation of particular genes can be applied to any type of transcription ailment, allowing similar vectors for both DNA and RNA viruses.

I found this article interesting because it involves the utilization of nanobots and gene therapy

I found this article at http://www.popsci.com/science/article/2010-03/nanotech-robots-deploy-cancer-fighting-rna

- Scott Blasczyk, VTPP 435-502

Monday, March 29, 2010

Replacement Bones

Growing replacement bones from stem cells to replace damaged or broken bones in the human body is becoming an exciting field. There are several researchers currently working on development of a procedure for creating the bone material, crafting it into the correct shape, and then filling it with bone marrow and other cells to get it to become like a real, living bone. Researchers at Columbia University are working with a "bioreactor" chamber that allows the new bone to flourish and grow. The cells that are put into the bone are taken from the patient to minimize the risk of immune response. Working along the same lines, researchers at Michigan are working on allowing the bone to be put directly into the patient's body, citing that the human body is the best incubation chamber available for a new tissue.
Independent researchers and experts agree that the greatest challenge is to keep the new bone alive and properly integrate it; the challenge of creating new bone in the correct size and shape is almost a routine process now. The method most commonly being used is taking a high resolution CT scan of a normal, healthy bone, and allowing a computer to cut out this digital shape from a block of bone material using a laser. This method allows absolute precision when sculpting the bone. In the future, it will be possible to craft all bones in the body, from the femur to the bones of the inner ear.
I found this article especially interesting because I didn't know it was possible to simply create a bone framework and then inject existing bone marrow cells into it, and have the bone flourish. Obviously it has to be under the right conditions, but still, the idea of being able to do this will completely replace having to have pins or titanium plates on bones.

http://www.nytimes.com/2010/03/28/health/research/28novelties.html?ref=research

David Szafron

One Gene Lost = One Limb Regained? Scientists Demonstrate Mammalian Regeneration Through a Single Gene Deletion

Once again it seems that science will be furthered by scientist stumbling on a pebble which would send them down a path not yet plotted. While conducting an autoimmunity experiment in 1996 using MRL (Murphy Roth Large) mice, Dr. Haber-Katz ran into a snag. A few weeks into the experiment, the holes pierced through the ears of the mice which were used for long term identification, were healed without a trace. This discovery sent the scientist of the lab into a scramble to determine what made these mice heal with no scars. The lab went in two different directions: one focused on the mapping of the critical genes that accomplished this feat, while the second concentrated of the behavior of the cells. Almost immediately, the scientist noticed the cells of the MRL mice were atypical, demonstrating differences in cell cycle properties as well as DNA damage. It was soon found that p21, a cell cycle regulator, was inactive in the cells of the ear of the mice. In normal cells, p21 blocks the cell cycle in the event of DNA damage. This blocking prevents these damaged cells from dividing and potentially becoming cancerous. It was for this reason that the scientists worried that by removing the p21 gene they would see a rise in cancer. While there was an increase in damaged cells there was no increase in cancer cells. This was attributed to an increase in apoptosis in the cells with the p21 gene removed. The increase of the regenerative cells and the increase in apoptosis allowing rapid division of cells without the loss of control"… is similar to what is seen in mammalian embryos, where p21 also happens to be inactive after DNA damage. Unlike most mammals, which heal by scarring, these mice heal by “…forming a blastema, a structure associated with rapid cell growth and de-differentiation as seen in amphibians.” "Much like a newt that has lost a limb, these mice will replace missing or damaged tissue with healthy tissue that lacks any sign of scarring," said the project's lead scientist Ellen Heber-Katz, Ph.D., a professor in Wistar's Molecular and Cellular Oncogenesis program.

The Wistar Institute. "One Gene Lost = One Limb Regained? Scientists Demonstrate Mammalian Regeneration Through a Single Gene Deletion." ScienceDaily 16 March 2010. 24 March 2010 .

Sunday, March 28, 2010

Natural Killer Cells Kill Harmful Cells with Nanotubes

Doctors and scientists have been aware of the presence of NK cells for a long time. These natural killer cells are our immune systems first line of defense against harmful cells ranging from those infected with a virus to cancerous tumor cells. According to past research, these NK cells destroy the harmful cells by connecting to them and creating an immune synapse connection. Once this connection is made the NK cells pass toxic molecules into the harmful cell which in turn kills the harmful cell to which it was attached. Recently a study was put on by the Medical Research Council and Association. This study showed that not only can NK cells kill cells by attaching to them, but they can also kill them by ensnaring them with a “bungee-like tube.” This tube it called a membrane nanotube and is attached to most NK cells. The NK cells use this tube as a whip to ensnare the harmful cells as they are essentially trying to escape. Once they have the harmful cells in their nanotube, they can either kill them from a distance or bring them back in for the previously stated method of destroying harmful cells. Researchers are hoping to learn more about the specifics of this method of killing harmful cells in the near future. From this study alone, they were able to get video of these cells in action, and now that they have seen this process happen, they are hoping to be able to find out more about how the cells are killed on a more biological and chemical level.

I think this is really interesting because not only did it help us gain a better understanding of our body’s immune system, but it also has hopeful applications for better drugs in the future. Researchers involved with this study claimed that once they gain a better understanding of this process, it would be very possible to create drugs to help NK cells boost their killing of harmful cells. This would be great and since these harmful cells are often cancerous and other major diseases, these could be some of the first steps into finding a cure for terminal illnesses that we can only dream about now.

http://www.sciencedaily.com/releases/2010/03/100308151053.htm

Robin Terry
VTPP 435-502

Fatty Foods May Cause Cocaine-like Addiction

A new study has recently come out that claims that the consumption of fatty foods may actually lead to a cocaine-like addiction which causes compulsive eating habits. The study, which was done on rats, showed that high-fat, high-calorie foods affects the brain in much the same way as these drugs. Drugs and over eating both over stimulate the pleasure centers of the brain; after awhile, these pleasure centers may “crash” meaning that even more food must be consumed to achieve the same amount of pleasure as before. The neurotransmitter dopamine is expected to be the culprit that leads to such gross over eating in rats and also in humans. When the rats in the study ate too much, levels of dopamine dropped, much the same way that levels are low in humans that are addicted to drugs like cocaine and heroin. Although, the study is quick to state that not everyone with low dopamine levels is going to be obese or an addict, it may be a good indicator of future obesity.

This article interested me because it puts a real medical spin on the problem of obesity in the U.S. Being supplied with this information may keep some people from over eating in the future. If more people knew that simply eating too much could become an addiction and lead to obesity in the future, fewer people may being the habit.

http://www.cnn.com/2010/HEALTH/03/28/fatty.foods.brain/index.html

Brittany Guth
VTPP 435-501

Late-Night Drinking has no effect on Test Taking Ability

This article was about how drinking a moderate amount of alcohol will not impair a person’s ability to take a test the next morning. The test was conducted on a group of 193 student participants who were given alcoholic/non-alcoholic drinks at night then took a standardized test in the morning. Each of the participants who drank alcoholic beverages were given enough alcohol to reach a BAC of 0.12. It was found that there was no statistical difference between the two groups. Drinking a moderate amount of alcohol the night before a test has no effect on test taking abilities.

This study did not take into consideration the student’s academic performance only test taking ability the morning after a night of drinking. In other words this study did not prove that students who binge drink are able to do just as well as a student who does not drink. It only proved that students who felt slightly hung over were able to answer questions as well as other students who were not hung over. It has been shown that students who drink regularly are unable to pay attention in class because they are hung over. This is due to drowsiness, head-aches, and general discomfort from the night before. This inability to pay attention in class can lead to no performing as well in class.

I found this article very interesting because as a college student I am very interested in my academic performance as well as having fun on Thursday nights. I think that it is interesting that students were able to perform the same after a night of drinking, but I don’t think that I would ever do this before a test. I think that the alcohol’s effects would not impair my thinking after I have sobered up but I would perform poorly because I wouldn’t have studied the material enough. Theoretically I think that a student who is prepared well in advance could perform the same after drinking. I also can relate to the studies statement that academic performance is related to drinking. I know that it is next to impossible to pay attention in class after “thirsty Thursday” thus leading to academic decline. I will still not drink on Thursday nights because I find my studies more important than having fun.

Andrew Ritchey
VTPP 435-502

http://www.dailyfreepress.com/news/study-late-night-drinking-no-problem-for-test-takers-1.2201531

Fat Helps Heal

3D cell structures can be achieved thanks to the trash of Deepak Negrath of Rice university. By trash I'm referring to a "contaminated" set of plates Negrath was attempting to grow cells in a scaffold. As soon as the cells secreted a sticky substance he saw it as contamination and discarded the plates. It turns out that sticky substance was extracellular matrix and just what he was trying to grow in the first place. This extracellular matrix was grown from adipose cells that, now, can grow and mature on a scaffold due to this research. This material can potentially be injected into the human body and help repair varying types of tissues with no rejection of material. Basically the fat cells are prompted to secrete basement membrane that mimics the architecture tissues natrually used in cell growth. This is literally a framework that cells attach to when they form a network. Once these cells have matrued into the desired tissue, they secrete another type of substance that breaks down and destroys the scaffold. This substance is called Adipogel and has proven to effectively grow hepatocyctes which are the primary liver cells used in pharmaceutical testing.

This can be very valuable to pharmaceutical companies for testing drugs in vitro. There's been something similar made called Matrigel but it's secreted by mouse cancer cells, thus why it can't be injected into humans.

If this research holds true, there would almost no strain on retrieving fat cells to use. Because fat is in excess in the body we can always get rid of it. There is another method being researched in nature nanotechnology taht uses magnetic levitation to grown 3D cell structures. While this is beneficial, fat cells are still more easily accessible. The goal is to use these fat cells as a feeder layer for human embryonic stem cells.

I found this interesting because while (especially these days) we see fat as an overall bad thing and something to get rid of, it can also be used to help and even heal our body. Also the fact that if this all proves true, the answer for stem cell scaffolding doesn't lie in something fancy and cool..it's just fat and that's pretty ironic to me.

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Friday, March 26, 2010

Development of a New Chitosan Hydrogel for Wound Dressing

This article explores new advances in wound dressing to decrease recovery time for cutaneous skin injuries. Skin loss can be traumatic to the body, causing fluid loss, hypothermia, scarring, and infection. If the organism survives the initial skin loss, the healing process is complicated and often long depending on the extent of skin loss. New research is being conducted to find biocompatible materials that can speed up the healing process to minimize dehydration, infection, and other problems with skin loss. Some researched materials include polymers extracted from the extracellular matrix, such as collagens and glycosaminoglycans. However, the article points out that their biological inertness makes them ineffective at speeding up the healing process. A material is needed that provides a good environment for certain healing process like fibroblast formation. The material described in this article is a chitosan hydrogel (CH). Chitosan is the deacetylated derivative of the natural polysaccharide chitin. Chitin is found in the exoskeletons of arthropods and some fungi.
CH is apparently very biocompatible, it provides some advantages for healing cutaneous wounds. It was proved to be non-toxic to cells, namely fibroblasts, in some in-vitro tests. Its chemical properties, mainly how it can form hydrogen bonds with water, help it slow down water loss when applied to wounds. The study in the article found that the hydrogel accelerated the initial healing process. There are graphs in the article that show the wounds treated with hydrogel were statistically-significantly-smaller than the control group's wounds up until 9 weeks (rats were used as specimens). This seems to suggest that the hydrogel can speed up the initial healing process and therefore make the wound less vulnerable in the first stages of injury due to infection, dehydration, and hypothermia.
I found this article interesting because it shows how current technology is advancing to provide ways to heal wounds by engineering tissues. It would be interesting if instead of using Neosporin to treat a minor cut, you slapped a pad of CH on it. The results and benefits of using CH to treat burn wounds on rats could mean compounds like CH could save critically burned patients from death by dehydration, infection, and hypothermia.




here is the article,
I had to search for it while being logged into the library.tamu.edu website:

http://www3.interscience.wiley.com.lib-ezproxy.tamu.edu:2048/cgi-bin/fulltext/122648466/PDFSTART




MICHAEL SERAFINO
VTPP 435-502

Cord blood stem cells help meet minority marrow needs

Diana Tirpak, a 68 year old retired nurse from Ohio suffered from leukemia, and her prognosis was looking grim if she did not receive a bone marrow transplant. Leukemia, as well as lymphoma and myeloma, patients usually require a bone marrow transplant, however, they must find a bone marrow donar from a close relative or from a national bone marrow registry. Even if a patient has a close relative that can prodive marrow, there is only a 25% chance of matching. And the national bone marrow registry only covers 60% of Caucasians and only 5 to 15% of minorities. Tirpak was facing death until her physician turned to new research that utilizes the umbilical cord newborns. The umbilical cord is rich in stem cells, which means they are easier to match than bone marrow because they have not yet developed into specialized cells. The treatment time is shorter, lasting about three weeks, as opposed to six to eight weeks like bone marrow transplants. Another patient, Nathan Mumford, an African-American college graduate, was diagnosed with leukemia and could not find a bone marrow match. Instead of continuing chemotherapy, he opted for a cord blood stem cell transplant. These transplants require the patients to undergo chemotherapy and/or radiation to supress the body's immune cells and to lower the risk of rejection. The stem cells are then injected into the body, where they travel to the bone marrow cavities and develop into new marrow.

Today, more than 200 hospitals nation-wide accept cord blood donations, which must be acquired immediately after birth and properly stored (via freezing). It is also processed into the national registry for matching to be made. However, one must realize that cord stem cell transplants carry the same risks and complications as bone marrow transplants, and patients undergo months of serious recovery. But if it is a viable option as opposed to death, then most patients would agree it is worth all the risks.

Source: http://www.cnn.com/2010/HEALTH/03/01/cord.blood.marrow.minorities/index.html

Nathan Poon
VTPP 435-501

More than 1 million baby slings recalled

Over 1 million baby slings have been recalled by Infantino LLC. The slings were recalled after several (at least three) babies died due to suffocation induced by the sling. A baby’s neck is too weak for the baby to turn his head. The design of the slings allowed the baby’s face to be pushed against the cloth. Unable to move his head, the baby slowly suffocated.

The design of the sling also allowed the baby to lie in a hunched position. This position restricts the airways. When the airways are restricted the baby cannot cry for help and slowly suffocates.

Infantino LLC is offering a free replacement product to everyone affected by the recall. The Consumer Product Safety Commission is currently working on establishing mandatory safety regulations for baby slings. While this is in the works, they are encouraging the industry to adopt voluntary regulations. There are currently no mandatory safety guidelines for baby slings.

This blog post is different from other posts on this blog. Instead of showing the latest and greatest technology, I showed you the tragedy and financial loss that can follow when products are designed poorly. As Biomedical engineers, we tend to think that our field is composed entirely of high-tech implants and artificial organs. True, these are in our field, but our field is much broader. Every device used by humans to treat disease, reduce the effects of aging, or assist in the care of the weak is an example of Biomedical Engineering. The moral of this post is to never dismiss a problem or concern in engineering because it is too trivial. I highly doubt the designers of the baby slings put much thought into the design of the slings. After all, people have been making these for centuries. But now, thanks to their negligence, at least three babies have died.

http://www.webmd.com/parenting/baby/news/20100324/1-million-baby-slings-recalled

Thursday, March 25, 2010

Lupus and Urine proteins

A new animal study was conducted at University of Texas Southwestern Medical Center. The main goal of their study was to find something in the urine that was unique to lupus kidney damage. This study is clinically useful for doctors who have to monitor the progression of lupus and how it is affecting the kidneys and the best current way to gain this information is an invasive kidney biopsy. Because testing the urine is noninvasive and cheap, this could be a much better way to monitor patients. Kidney damage causes the most deaths for lupus patients and is therefore very important to monitor for physicians for proper treatment. The researchers found seventy one different proteins in the mice urine only during kidney damage. Of these, they chose four that were in large quantities and would possibly be the best markers. These four proteins are protease, PGDS, SAP and SO. Even though these are proteins found in mice kidneys, there are human equivalents that could be used to monitor human patients. Not only would this information help monitor patients, it could also help determine the mechanisms of lupus as well according to Dr. Mohan. Along with lupus, proteins could also signal kidney damage in other diseases such as high blood pressure and diabetes.

from "Urine Protein Test Might Help Diagnose Kidney Damage from Lupus"
http://www.sciencedaily.com/releases/2010/02/100216101208.htm



Stephen Infanger

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Stem Cells Create Windpipe

A young boy from the UK has been fortunate to receive a potentially life-saving windpipe transplant to correct his rare condition called Long Segment Congenital Tracheal Stenosis. The disease plagues the patient with breathing difficulty on account of an extremely narrow airway. To comprehend the severity of the disease, know that the boy had been born with a tracheal diameter of roughly one millimeter. One could equate the affliction to breathing through a straw. Doctors had previously operated on the boy last year by expanding his windpipe with a metal stent; however, complications emerged from erosion of the metal. The new transplant, being composed of donor trachea turned into a collagen scaffold, is lined with stem cells taken from his bone marrow. Over the next month, these cells should specialize and manifest themselves into a working trachea.

Though the boy is the first child to undergo the procedure, the transplant itself is not the first of its kind. A woman in 2008 underwent the same procedure, but hers was only a segment of the windpipe. The boy’s in fact the first whole tissue engineered windpipe has been transplant. Stem cell organ treatment is still at the baby stages of actual use, but this operation has proven to a milestone for future endeavors. The donor windpipes were treated with a cocktail of chemicals to prompt the stem cells to grow into new tissue once implanted. The doctors involved believe they have pioneered a new technique that can be done cheaply and safely. The future of transplanting other organs such as the esophagus may depend on how well the boy’s organ develops and how well the body accepts it.


http://news.bbc.co.uk/2/hi/health/8576493.stm

Renal Capsule as a Stem Cell Niche

There has been known for a while that there are stem cells stored, so to speak, within the renal tubules and papillary area. Scientists in New York conducted a study to see if renal capsules harbor stem cells as well and whether these cells can be called upon ischemic injury. More specifically, if these cells can be recruited to the renal parenchyma.
It was demonstrated (in vitro and in vivo) that there are stem cells throughout the renal capsule and that they are, in fact, close to the blood vessels.Renal capsule derived cells exhibited self-removal, clonogeniciy and multipontency in differentiation conditions--all stem cell characteristics. In vivo, a directed migration of the marke cells (stem cells) was shown to the ischemic renal parenchyma. Decapsulating of the kidneys during ischemia resulted in a modest, but statistically significant deceleration of recovery of plasma reatine compared to ischemic kidneys with the intact renal capsule. Therefore, one can conclude that the renal capsular cells may contribute to the recovery from ischemia.

I picked this article because I didn't know that the kidneys has stem cells to begin with. So, it was even more interesting to me to find out that not only does the kidney have stem cells in several locations, but there are finding more. Moreover, these stem cells can be called upon injury. To me, this just validates the fact that the kidney is so important to the human body that it has several "emergency plans" to make sure to keep the kidney is in good conditions.

http://ajprenal.physiology.org/cgi/content/abstract/00406.2009v1

Contact lenses may alert diabetics to blood sugar variations

Diabetics have very tedious schedules for monitoring their health in comparison to many other groups of people with illnesses. Blood sugar levels have to be checked multiple times in order to properly maintain a healthy state of living and this often requires pricking a finger or drawing blood in some way that can make some people squeamish just thinking about it. A new method, however, could be painless and more efficient while better monitoring blood sugar levels. Researchers have recently developed contact lenses that change color in response to increases or decreases in the blood sugar level. This occurs due to nanoparticles embedded in the lenses that chemically react to the glucose naturally present in tears. Ultimately, these lenses along with proper responses by the diabetic can greatly help diabetics monitor their insulin levels and thereby prevent the medical complications that include fatigue, nausea, problems with vision, and a litany of other conditions that insulin affects.

While my family is not much affected by diabetes as a whole, there are some members of my extended family that are affected by diabetes and would benefit from advancements in monitoring their diabetes. This article interested me because of the simplicity that the contacts add to the diabetic’s daily routine and the simple way that diabetic treatment is implemented. For many diabetics it seems like the biggest hassle is simply keeping up with their blood sugar levels and with these new contacts much of the hassle may go away.


http://www.themedguru.com/20091228/newsfeature/contact-lenses-may-alert-diabetics-blood-sugar-variations-86131597.html

Wednesday, March 24, 2010

Cancer genes silenced in humans

This is a neat article depicting how actualy nanoparticles or nanobots are actually being used to deliver a lethal blow to cancer cells, with the first human trial being a success of no side effects. By sneaking into the cell, it evades the immune system and delivers the siRNA or the silencing RNA into the cancer cell.

The nanobot is being delivered by a research team at the California Institute of Technology headed by Mark Davis. The team has discovered a safe mechanism for delivering RNAi sequences into the cancerous cells. Ribonucleic acid interference (RNAi) attacks specific genes in the malign cells and disables functions inside, killing them.

The bots are about 70 nanometers of two polymers and a protein which will attach to the surface of the cell. They are designed to carry the siRNA to deactivate the production of a certain protein and starving the cell to death. Also, once the job of the nanobot has been accomplished, the nanoparticle will break itself down and get eliminated by the body through urination.

I feel like our nanobot projects in class are actually becoming a reality.

Source:
http://media.caltech.edu/press_releases/13334

Do Statins Work Equally for Men and Women?

http://www.time.com/time/magazine/article/0,9171,1973295-1,00.html

Over 24 million people are using drugs to combat their cholesterol in the U.S. Statins, such as Lipitor, Zocor, and Crestor, are designed to clear away LDL cholesterol, waxy plaque buildup which clogs the arteries and can ultimately lead to heart attacks and strokes. Many people who take statins do not have heart disease and take the drug as primary prevention.

Roughly 12 million American women are routinely prescribed statins, despite their serious side effects and lack of evidence to prove that they prevent heart disease in women. Statins have negative side effects such as starving the onset of heart disease in healthy at-risk adults. Many of the life-saving benefits statins provide to men do not cross the gender barrier in helping women. Women are also more likely to suffer from the serious side effects of taking statins, such as memory loss, muscle pain, and diabetes. In women who already have heart disease, statins reduce heart-related deaths but do not reduce the overall deaths.

In the 1990s, women were not involved in drug trials to protect pregnancy and avoiding affecting hormone fluctuations. Since then, there have been many studies concerning how different disease may affect women in very different ways from men.

There was a trial called the Jupiter Trial. The goal of the study was the compare the effectiveness of Crestor in healthy patient. The study showed that women who took 20 mg of Crestor daily for an average of 1.9 years have a 46% reduction in cardiovascular events. This result is simlar to the 42% reduction in men. Other researchers argue that the evidence is cloudy and that the benefits in women are much less extreme than in men. An example of this is that women are more likely to develop diabetes from taking statins and that 1.9 years is not a long enough time to show all of the side effects.

One theory why statins do not show equal benefits for men as women is that since women have a lower risk of heart disease, it is more difficult to lower an already low risk. Lower body weight and hormonal fluctuations might also play a role. However, many researchers also argue that the benefits should outweight the risks.

- Sarah Biemer

Tuesday, March 23, 2010

Nanobots play a role in Gene-Manipulation Therapy

For the first time in humans, scientists have successfully used small interfering RNAs (siRNAs) to directly interfere with the genetic mechanism of tumor/cancer cells and stop the production of a critical toxic protein that causes cancer cell proliferation and migration. SiRNAs are a class of double-stranded RNA molecules, composed of about 20 to 25 nucleotides, that are involved in the RNA interference pathway. When inserted into the cell, the siRNAs used cleaves specific mRNA molecules that are ordinarily used to make the proteins. However, since its discovery in the late 1990s, scientists have been struggling with how to get the siRNAs to the appropriate cell and make sure that the siRNAs did their job without any off-target effects.

Recently, a research team from the California Institute of Technology devised a nanoparticle system that, when injected into the body, would guide the siRNAS to the cancerous cells and deposit them to do their assigned task. An early phase clinical trial was conducted that involved patients with Melanoma, a virulent form of skin cancer. They injected the patients with cargo-laden nanoparticles directly into the blood stream as opposed to directly into the tumor as many other researchers have done. The nanoparticles made its way smoothly into the target and released its siRNA cargo that would go on to cleave the targeted mRNA and ultimately halt the cancer cell proliferation. Precision of the process is extremely crucial to the treatment, first in targeting the correct cells and next in cleaving the correct location on the targeted mRNA. These nanobots were able to just that. Now it is possible to go selectively at proteins involved in the disease and not have off-target effects.

Though further refinement and optimization of this carrier system is still needed to provide a highly selective way to affect cancer cells and tumors that have until now eluded drug therapy, it won't be long till we see nanobots as a prevailing method of delivering treatment to cancer cells.


http://news.yahoo.com/s/hsn/20100323/hl_hsn/genetargetedcancerfixcouldbeabreakthrough

Biomaterial That's Bone-Hard

Rupturing your crucial ligament can be a painful process and requires two surgeries, one to repair the torn ligament with a piece of tendon from the leg and this is put on the bone with an interferential screw. However, the screw is not biodegradable and must then be removed in a different procedure. Here is where the researchers at Fraunhofer Institute for Manufacturing Engineering and Applied Materials Research (IFAM) in Bremen come in, they have created a "robust bioactive and resorbable screw by means of a special injection molding process" which usually biodegrades in 24 months (depending on the composition). The idea of biodegradable screws are not a new idea as polylactic screws have been used for a while, but they have the disadvantage of leaving holes in the bone, the IFAM decided they wanted to create a better product and created the new screws using polylactic acid and hydroxylapatite, a ceramic which is the main constituent of the bone mineral. Since the screws are being formed in a mold, they can more easily be tailored to the individual patient's needs and allows for a more complex geometric shape to be made. the screws have many of the same properties of bones and almost have the same compressive strength of 130 N/m^2 where bones are between 130-180 N/m^2. A final point is how much energy can be saved using this process, where the other powder injection models of screws need 1400°C this only needs 140°C saving tons of money on energy costs.



I chose this article because it shows that improvements can always be made on any procedure and it all starts from engineers thinking outside of the box and coming up with ideas that limit patient's time in recovery. To me, another interesting point is that nothing is ever better than what you "came with."

Saturday, March 20, 2010

Medco, Mayo Clinic study finds reduced hospitalization rates with genetic testing

March 16, 2010 | Mike Miliard, Managing Editor

ATLANTA – A simple genetic test can reduce hospitalization rates by almost a third for heart patients taking warfarin, the world's most-prescribed blood thinner, according to a study released today by researchers from Medco Health Solutions, Inc. (in association with the Medco Research Institute) and the Mayo Clinic.

Announced at American College of Cardiology's 59th annual scientific session, and due to be published in the Journal of the American College of Cardiology, it is the first nationwide prospective study examining outcomes when incorporating genetic testing into the management of warfarin as part of the usual care of patients.

Warfarin, which is marketed under the brand names Coumadin and Jantoven, is a blood thinner that is exceptionally difficult to properly dose: The two million patients who start the drug each year have widely varying responses to the medicine due to a variety of factors – including genetics. It's estimated that perhaps 20 percent of patients are hospitalized for bleeding within six months of starting the drug.

The comparative effectiveness study, conducted in nationwide "real world" settings, found that testing for a patient's unique genetic predisposition can significantly improve warfarin's safety and effectiveness by providing information about the patient's sensitivity to the drug, revealing that patients whose therapy included genetic testing were 31 percent less likely to be hospitalized for any cause, and 28 percent less likely to be hospitalized for a bleeding episode or thromboembolism when compared to patients using the blood thinner without genetic testing.

"Warfarin represents an excellent example of how to take the modern science of genetic testing and apply it to making an older drug more effective and safer to use," said Robert S. Epstein, MD, lead author of the study and Medco's chief medical officer and president of the Medco Research Institute. "These results show that we can greatly reduce hospitalizations, and their significant costs, by making genetic testing routine early in a patient's therapy with warfarin."

The Food and Drug Administration requires a so-called "black-box warning" on warfarin – the leading cause of drug-related emergency room visits among the elderly – that describes the bleeding risk and recommends regular monitoring to ensure the patient is responding properly to the dose. The FDA recently approved a labeling change that provides dose recommendations based on genetic test results....

I found this article very interesting due to the fact that it offers new options with an existing technology which is simple genetic testing to reduce the amount of people being hospitalized. I thought it was interesting how the study was directed for a blood thinner which we went over how they function in the body and how these new technologies such as genetic testing can help improve existing drugs. The amount of tests and checks available for different medicines have grown exponentially and as we see in this article can help improve existing medicines.

David Figueroa

Thursday, March 18, 2010

'Silver Bullets' for Cancer Cells

Scientists in St. Louis are currently in the process of developing a 'silver bullet' for cancer. The term silver bullet comes from mythological stories, in which supernatural creatures were believed to only be killed by silver bullets. In this case, scientists are using photothermal methods in order to treat stubborn cancers. Specifically, the scientists are using gold nanocages. Nanocages are gold nanoparticles which are created by the reaction between silver nanoparticles and chloroauric acid. These special particles are biocompatible. These particles are special because when used in cancer cells, they can be injected into the body and they specifically will gather in locations which contain tumors. After the nanocages accumlate in the correct locations, a laser is shined at this location. The laser will kill some of the tumor cells in the vicinity. However, when the nanocages are exposed to this laser, they will absorb a lot of the heat, and through a reaction with the laser beam will convert light energy to heat energy, and this will warm up the area in which there is a tumor and kill many tumor cells. In the early trials, the scientists used a low levels of the laser treatment, but the results were very promising. In order to obtain the maximum absorption, the nanocages are configured to an optimum wavelength, which in this case was 800 nanometers. At this wavelength, the light is able to pentrate several inches into the body, which enables the treatment of many types of tumors. When this treatment was tested on rats, the proteins which help enable the tumor cells to function begin to denature at high temperature (42 degrees Celsius). This was verified by CT scans, which show the activity of tumor cells in the treated regions is much fainter than control subjects. Overall, this treatment is interesting because it is a much more non invasive method than many of the current methods of cancer treatment. There is also a much lower risk of side effects such as those from chemotherapy. I found this article interesting because I would like to focus my future research on cancer related topics, including the development of more non invasive methods. I think the continued improvement of the nanocage method will be interesting to see over the next few years.

Source:http://www.sciencedaily.com/releases/2010/03/100312164701.htm

Cancer Vaccine

http://www.cnn.com/2010/HEALTH/03/04/vaccine.brain.cancer/index.html

The people working at Duke University, researching new therapies for cancer, have come up with a new approach towards its treatment that involves a sort of vaccine. The vaccine itself is not an ordinary vaccine, in the sense that it isn’t applied before the patient gets the disease. This vaccine, instead, works by turning the body’s own immune system against the cancer cells, something that scientists have been working on for a very long time.

The previous problem with such an approach is that there was almost no way to distinguish these cancer cells through any type of known marker, obviously because they were made by the body itself. Now, however, they seem to have found a marker that just might be unique to these cancerous cells—EGFRviii, or “EGFR factor three.” Using this newfound marker, researchers at both Duke and UCSF have created drugs that send the immune system attacking cells that make this protein, which is unique to roughly 40% of the cancerous cells, enough to save a life.

The only difference between the Duke research and that at University of California, San Francisco is that UCSF takes a much more aggressive and somewhat more expensive approach. It involves make a drug unique to every patient. The vaccination would be built off of that person’s own form of cancer, making it much more effective at treatment.

These new developments lead the way in how medicine will approach problems in the future, never afraid to take a step in the wrong direction as long as it means a possibility of ingenuity.

-Ryan Rihani

Wednesday, March 17, 2010

Direct Injection of Gold Nanoparticles Into Tumors Opens Door to New Treatment for Pancreatic Cancer

Pancreatic cancer is thought to be one of the most deadly cancers. The current treatments for it include chemotherapy, surgery and a few other methods. Unfortunately, none of these have a high success rate. In fact, most of these “treatments” for pancreatic cancer are not very helpful. One of the reasons is that scar tissue forms around the cancer, which insures that the drugs normally used to destroy the cancer are ineffective. They are unable to reach the tumor due to the scar tissue surrounding the cancer.

Fortunately, researchers at Northwestern University have come up with a new potential treatment for pancreatic cancer. It is currently undergoing extensive research and testing at Northwestern University. The researchers have created gold nanoparticles which are to contain an cancer-destroying agent. The process used to deliver these nanoparticles directly to the tumor in the pancreas involves a new delivery method called nanoembolization. This technique drastically increases the concentration of nanoparticles inside the tumor.

Researchers have used this injection technique of “nanoemboliztion” in animal testing. A catheter is used to inject the golden nanoparticles into the body, directly to the tumor. The catheter is placed in an artery that will feed the tumor. This process is to be done without the invasion of surgery. This direct catheter injection offers many advantages that other cancer treatments do not ensure. Dr. Omary, a professor at Northwestern University states that “with this catheter delivery, more drug can go directly where we want it: to the tumor itself.” Therefore the drug will have more of an effect on the tumor (in that a majority of the cancer-destroying agent actually reaches and interacts with the cancer) In other cases where the injection is done through the vein, the agent may not go where it is intended.

I found this article very interesting and optimistic. I think that this new technique of injection, “nanoembolization,” offers an advantage in that it enables nanoparticles to be directed exactly where they need to be. The more nanoparticles filled with cancer killing agents that can be concentrated in the tumor, the higher the chances are of destroying more of the pancreatic cancer. This is the goal that numerous researchers have been working on for a long time. With every new research development made, we move closer to finding a complete treatment for cancer. This more direct injection technique will hopefully be a stepping stone that will lead to more non-invasive techniques of treating cancer.

http://www.sciencedaily.com/releases/2010/03/100316101356.htm

A Reboot for the Immune System

Autoimmune diseases comprise some of the most persistent and debilitating diseases known: rheumatoid arthritis, lupus, multiple sclerosis, type 1 diabetes, and others. Though they are all unique, they have a common underlying cause: a malfunctioning immune system. Through still not-entirely-understood mechanisms, healthy immune cells patrol the body and know when to protect and when to attack. In these autoimmune diseases, for reasons unknown, specific body cells are no longer identified by the immune system as "allies" and become "the enemy." In the case of type 1 diabetes, a number of immune cells go awry and begin to destroy pancreatic beta cells, the site of insulin production, which is a necessary component in the body's regulation of blood glucose levels.

Immunosuppressant drugs exist, but they are very general and attack the entire immune system, leaving the patient susceptible to all sorts of infections, meaning a more-targeted drug is needed. Jeffrey Bluestone, the current director of the Immune Tolerance Network and the Diabetes Center at the University of California at San Francisco, has spent the last 30 years developing a new drug derived from an organ-transplant medication that can be used in the prevention the progression of type 1 diabetes. He and his research partner, endocrinologist Kevan Herold, aren't 100% sure how the drug, known as an "anti-CD3 monoclonal antibody," works, but they know it selectively binds to the surface of malfunctioning T cells and inhibits their attack on the pancreas while increasing the number of healthy T cells. The drug and others like it have shown extreme promise in human trials, halting beta cell destruction and sometimes even resulting in increased insulin production. It's hoped that this anti-CD3 drug will be FDA-approved and available in as little as two years. When it becomes available, it will be the very first type 1 diabetes medication that actually targets the cause of the disease.

This article grabbed my interest because a best friend of mine has type 1 diabetes, and I've seen what a pain it is to always have to check your blood sugar and to give yourself insulin. He has to take his pump everywhere he goes and a couple weeks ago he got a massive infection in his thigh where he gave himself a shot. This is promising not just for my friend but for people with all sorts of autoimmune diseases, which have been viewed as chronic and incurable for a long, long time, but may not be for much longer.

http://www.popsci.com/science/article/2010-02/rebooting-body

Monday, March 15, 2010

Alternative To Open Heart Surgery

In this article, a alternative to open heart surgery is presented to fix a "leaky" heart. This problem occurs when the mitral (bicuspid) valve does not shut all the way and blood is allowed to flow in the retrograde direction. This can cause major problems such as fatigue, exercise intolerance, shortness of breath and swelling. This dangerous because there is not enough blood being circulated around the body.

Traditionally, this problem was fixed through open heart surgery, an extremely invasive procedure with many months needed for recovery. If a patient was too old or weak, open heart surgery could sometimes doe more harm than good. This is where the new procedure becomes useful. The procedure uses a catheter inserted through the femoral artery in the groin. After the catheter is directed into the problem area of the heart, a clip is passed through the catheter and holds the mitral valve together insuring no "leakage" occurs. The catheter is then taken out, but the clip stays in place.

The procedure takes about two hours to complete, which is the same amount of time that open heart surgery usually takes. The alternative procedure is beneficial in the fact that it cuts recovery time down to only a few weeks. It is also a lot less invasive than the open heart surgery.

I thought this is really interesting because it allows patients who are old and cannot handle open heart surgery to fix their heart. Even though the procedure takes the same amount of time the recovery time is a lot shorter and the procedure time is a lot less harsh on the body. Therefore, even stronger patients may opt to use this procedure instead of open heart surgery to fix a leaky mitral valve. I also thought this was interesting because we had learned all about the valves and heart in class, so it was interesting to see actual applications being researched and developed in the areas that we had studied in class.

Article Link

Jessica Sabbagh
VTPP 435-502

Saturday, March 13, 2010

PEGylated Dendrimers: A Novel Mechanism of Drug Delivery

Researchers have developed a new way to deliver medications by using PEGylated polylysine dendrimers. These are 5-10 nm drug delivery systems whose properties can be altered by changing the peripheral sites surrounding their core. The new technique shows particular promise in fighting certain metastatic cancers, HIV, and other diseases which are spread by the lymphatic system.

The dendrimer itself consists of an inner core surrounded by layers of polymer. These layers provide each dendrimer with surfaces for drug attachment as well as polyethylene glycol (PEG) attachment. PEG attachments are important in increasing the amount of time that the delivery system can exist in the body before breaking down. The interesting finding is that the body’s decision to place these systems depends on the length of attached PEG chains. A longer PEG chain seems to have an easier time entering into the lymphatic system, while shorter chain systems are quickly absorbed into the blood. Early observations indicate the possibility that a dendrimer system can be tailored based on the medical application to reach target sites.

This article caught my attention primarily because it is similar in spirit to last semester’s device design project. Researchers are actually developing devices on the nanoscale that target specific sites and areas in the body. These researchers utilized PEG layers in precisely the same manner that many of us did. That is, to disguise the system from the body’s defense mechanisms. It wasn’t until after many tests were performed that the special properties of these devices were realized though, which would have been the next step for us as well.


http://www.sciencedaily.com/releases/2010/03/100311101612.htm

Sunday, March 07, 2010

Scanning for skin cancer

Cancer cells divide more rapidly than normal cells, thus generating more energy as heat. However, the temperature difference between healthy and cancerous skin cells is extremely small. This is why it is very difficult to detect the melanoma when it is in stage 2 (still only on the skin) before it progresses to stage 3. At this stage, the melanoma hits the lymph nodes or even the bloodstream and thus it becomes more difficult to treat. To help the diagnosis of cancerous melanoma early on, researchers at John’s Hopkins have designed a noninvasive infrared scanning system that helps physicians determine whether pigmented skin growths are benign moles or actual cancer. The device works by looking at the tiny temperature difference between healthy tissue and a growing tumor.
To make the difference in temperature between the healthy skin and the melanoma stand out, some steps have to be taken before the device can detect it. First, they cool a patient’s skin with a one-minute burst of compressed air. When the cooling is stopped, they immediately record infrared images of the target skin area for two to three minutes. They do this because cancer cells typically reheat a lot quicker than the healthy cells. This difference in reheating can be captured by the infrared camera and viwed through sophisticated image processing.
Currently, theirs is a pilot study being conducted where lesions that have been dermatologist identified undergo the procedure and then a biopsy is taken to prove whether or not the result obtained by the infrared device was correct. This technology could also be incorporated into full-body scans in the future for patients with a large number of pigmented lesions.

Geraldine Pena-Galea
http://gazette.jhu.edu/2010/03/01/scanning-for-skin-cancer-infrared-system-looks-for-melanoma/

A novel technique to study protein folding in vivo

Researchers at the University of Illinois have created an innovative new technique to study the dynamics of protein folding in real time. Martin Gruebele’s hypothesis before he developed his novel technique was that protein folding was largely influenced by its mechanical environment, and thus could not be studied properly in a simple, artificial environment. In another words, he stated that when protein folding was studied in vitro, there was only one possible outcome to the research. However, in reality, the mechanical environment in which a protein folds largely determines the ultimate outcome. Gruebele’s goal was to be able to study proteins in their natural environment, a live cell.
In order to study protein in vivo, Gruebele and his team developed a technique called Fast Relaxation Imaging, which combines fluorescence microscopy and fast temperature jumps. Fluorescence microscopy is a common tool used to take images of the inside of cells; however, one can only observe dynamics in a cell that happen over long periods of time. Since most protein folding happens on the time scale of milliseconds, fluorescence microscopy was useless in terms of tracking the dynamics of proteins. Fast temperature jump is a technique that has been used to study cellular chemical kinetics for a while. Yet, this method restricts the user to in vitro experiments, thus simplifying the mechanical environments of cells that have proven vital in terms of in influencing protein folding.
With Fast Relaxation Imaging, laser pulses are used to achieve temperature spikes inside the cell, while an inverted fluorescence microscope is utilized to observe the protein dynamics in vivo. Using this novel technique, Gruebele discovered that rates of protein folding studied in vitro differed than those studied in vivo. Overall, the thermal denaturation and folding kinetics were slower when studied in vivo. However, his results varied depending where inside the cell the protein was. Gruebele says that this heterogeneity can be attributed to the “different channels and cellular furniture that the protein might bump into.” Gruebele’s technique is the first to take this heterogeneity into account.
Using Fast Relaxation imaging, Gruebele hopes to advance research on neurological diseases such as Alzheimer’s, and Huntington’s Disease.
This article can be found at : http://www.sciencedaily.com/releases/2010/02/100228131331.htm
Oscar Carrasco-Zevallos

Thursday, March 04, 2010

Treating Migraines

There is a new, promising, non-invasive treatment option for people who have migraine with aura. This treatment involves the use of a small device that will deliver a magnetic pulse to the patient's head. If done at the first sign of symptoms, this device allows the patient to be pain free for up to 48 hours with little to no side effects.

Migraine with aura is a special type of migraine that has additional problems beyond just the headache. Patients with this condition also experience visual spots, temporary regions of vision loss, numbness, and weakness, among other things.

Using this new treatment would allow these patients to have a more normal life. The magnetic pulses disrupt the electrical events in the brain that cause the symptoms of migraine with aura. Since this device is hand-held, it would also not be difficult to use.

I was interested in this article because I like reading about new treatments that are non-invasive and drug-free. Migraines are really painful and I know a few people who suffer from them, so it nice to see that there will be new easy treatments available for them to relieve the pain.

Sandhya Ramesh
VTPP 435-502
Link