Friday, November 30, 2012

The use of cochlear implants for single-sided deafness in children

Cochlear implants or "bionic ears" are electronic implants used to help people who are deaf or have profound difficulty hearing to be able to hear. Most people who get the implants only get one- even though they typically cannot hear on either side. Also, most of the people receiving the implants are adults. I was surprised to learn that elsewhere, like in the EU for example, it has become a relatively common practice to provide the implants in young children. In the US it continues to be unusual for the procedure to be done in this early. The FDA has also not approved the use of cochlear implants for single-sided deafness. This particular article details a Colorado physician's successful attempt to do both of these things: perform the surgery on a 9-year-old girl with single-sided deafness. With time, it is thought that this sort of procedure will become more accepted and more widely performed.

This article caught my eye as one of my friends had used hearing aids since he was very young, but he recently received a cochlear implant and it worked out a lot better for him. It seems unfortunate that this sort of technology is available and is in widespread use elsewhere, but can be inaccessible for some people here simply because there haven't been any large clinical trials performed in this country, yet.

The news article.

Scientists Use Prosthetic Device to Restore and Improve Impaired Decision-Making Ability in Animals



In this study performed by Wake Forest Baptist Medical Center, researchers attempted to record neuronal patterns and then use these records to stimulate the brain to make a specific decision. In this study, primates were trained to select a specific image when shown a list. Researchers then recorded the neuronal pathway used to make this decision by using a multi-input multi-output (MIMO) mathematical model to record the firing patterns of neurons from the prefrontal cortex. MIMO was developed by the University of Southern California and is a prosthetic device that can detect neuronal input, record input, and play back a previous input. Therefore, when implanted in primates with brain injury (cocaine in this case) replaying the recording would allow the mentally impaired primates to make the correct selection. The next step in this research would be an implantable device that could help recovery from brain injuries.
This article is incredibly interesting to me on account of the fact that my grandmother died from Alzheimer’s. Therefore, any research done toward correcting improper brain pathways could greatly assist in curing neurological disorders which could include this disease. This technology may also be accompanied by some ethical issues, however. I worry that a device that can influence others to make certain decisions would not be as widely accepted by most of the population regardless of its usefulness in helping patients with brain damage perform daily tasks.
http://www.sciencedaily.com/releases/2012/09/120913203915.htm

Self Assembled Drug Bearing Nano-rods Used to Treat Tumors


     
           Researchers at Brigham and Women’s Hospital have created a self-assembled, multi-functional, responsive gold nano-rod that is able to deliver the chemotherapy drug doxorubicin in response to a near-infrared (NIR) light stimulus.  The NIR light, which is minimally absorbed by skin and tissue, is absorbed by the gold nano-rods, which causes them to release the chemotherapy drug and ablate the tissue as well.  Preclinical models have shown that the self-assembled nano-rods are highly effective at targeting and eradicating the tumor cells while still being able to stay under the radar of the immune system.  The researchers are still running more pre-clinical models before testing the safety and efficacy of the platform in human trials, but the nano-rods show hope for a possible noninvasive way to remove tumors in the near future.
            I found this article interesting because it shows the progress of nano technology and its possible effectiveness in treating cancer.  It makes me wonder if similar nano-rods could be used to ablate plaque and target drugs in the coronary arteries.  I also found the NIR technology very interesting.  It seems like NIR tech could offer a wide range of uses in the future.

Thought-Controlled Prosthesis Changing Lives of Amputees





Thought-Controlled Prosthesis Changing Lives of Amputees

 (http://www.sciencedaily.com/releases/2012/11/121128093438.htm)



A new form of prosthetics use a type of signaling called oseointegration to more accurately recreate the lost limb. Normally, electrodes are placed on the skin and send messaged to the prosthetic telling it which of the preprogrammed motions it should execute. The electrodes have difficulty reading signals because they are constantly shifting on the skin and the person’s sweat distorts the signals. This is method is so unreliable and limited that it is only accepted by half of amputees. Oseointegration gets around this problem by attaching the electrodes directly onto muscles and nerves, close to the prosthesis. This gives the electrodes protection and more accurate readings do to their close proximity to what they’re sensing. Even better, the electrodes are able to send signals back to the brain, acting as muscle spindles. Osteointegration will be used in prosthetics starting this winter.

I find this article incredibly fascinating and exciting. Prosthetics are what got me interested in biomedical engineering in the first place – specifically integrating them with neural signals. I can’t wait to see where this new technique goes and I hope to see it in the news – for positive reasons – soon.  Thankfully, I don’t know anyone who will be directly affected by this, but it is still interesting.

A Better Solution for CAD than Nanobot

   In our project, we were asked to design a nanoscale device that would treat coronary artery disease. The main objective was to safely remove the plaque along the artery walls. CAD is dangerous because it can restrict the blood flow in the artery and potentially lead to a heart attack.
   But what if there was another solution that didn't include sending robots into the body? Researchers at  UC Davis have conducted experiments on mice in which they were injected with ALDH bright cells and it induced angiogenesis in regions of the body with ischemia. ALDH bright cell is a type of stem cell that contains all 3 of the most primitive subtypes of stem cells and a high concentration of the enzyme aldehyde dehydrogenase. The ALDH was injected into the limbs of the mice and they "homed" into areas of low blood flow and promote angiogenesis. The study is in the stage where it will readily be available for human clinical trials. The trials are readily available because they already administer human stem cells into mice. The research group at UC Davis say that they want to provide treatments for peripheral artery disease within the next year.
   The results from this experiment provide a potential treatment for many diseases that restrict blood flow because of the promotion of angiogenesis. It also shows the incredible potential of stem cells and reasons why we should continue to fund it.

http://insciences.org/article.php?article_id=5209

sleep deprivation affects your immune system

This article talks about how the lack of sleep affects your immune system. They made experiments on middle age people and tracked their sleep patterns and studied how strong an immune response they showed to a standard three-dose hepatitis B vaccine. People who got less than 6 hours of sleep per night were less likely to show good response to the antibodies of the vaccines.

Sleep deprivation is very common in Americans and may have other consequences like weight gain, diabetes, heart attack, stroke and even breast cancer. This risk could be related to changes in hormone levels , these alter levels of the hormone melatonin in the body. When people are sleep-deprived there are fluctuations in cell types which is important in antibody production, there are also alterations in some hormones that influence the immune system like cortisol and growth hormone.

This was brought to my attention since is common among college student to sleep less than usual during periods of high levels of stress, which may affect us in our performance in school, besides having physiological effects on us.

http://healthland.time.com/2012/08/01/why-lack-of-sleep-weakens-vaccine-effectiveness/

Migraine Sufferers Find Relief From Handheld Magnetic Device

Link Here
The above article talks about how a recent UK double blind study has found that by scanning the brain at the onset of a migraine headache, using a handheld magnetic field generating device, symptoms of the migraine, including pain, vertigo, nausea, and sensory sensitivities, can be alleviated. Use of this device also allows those who normally suffer from the migraines to have an option beyond painkillers, which can lose their effectiveness over time and have serious side effects. The device seems relatively convenient, with the article stating its cost at $500 and it being the size of a radio. Switching patients to a device mediated cure would also significantly reduce drug costs of the headaches, since the device is reusable and in the long run probably less expensive than a lifelong regimen of medication. The success rate of the device was fairly high in the study conducted, with the device (called the non-invasive single pulse Spring Transcranial Magnetic Stimulation Device, TMS for short)  having 63% of participants experience reduced symptoms and having 53% of participants experience fewer headache days.

The subject is important to me because both my mother and girlfriend frequently experience severe migraines. A treatment that doesn't involve strong painkillers would be optimal since current drugs for migraines are expensive and occasionally addicting. I also found this article of interest because non-invasive treatments for conditions are on the rise. The use of ultrasound and magnetic fields to cure diseases is innovative and something that would be interesting to work on in the future.

Researchers Turn Viruses in Molecular Legos

Researchers Turn Viruses in Molecular Legos

The article can be found here.

Researchers at the University of California, Berkeley, funded by the National Science Foundation, the National Institute of Dental and Craniofacial Research and the Defense Advanced Research Projects Agency, have developed a "self-templating material assembly" for synthesizing complex structures of helical proteins and other macromolecules, such as collagen. The researchers studied the factors influencing the construction of hierarchical structures, observing in particular how the alignment, twist, and shape of the collagen fibers helps determine their optical and mechanical functions: Collagen gives structure to transparent corneas, blue skin of various animals, and even teeth!

The researchers then chose to use a saline solution containing varying concentrations of  the M13 bacteriophage because its shape closely resembles collagen fibers. They covered glass plates in the virus, and by adjusting the concentration of viruses in the solution and the speed with which the glass is pulled, the researchers controlled the liquid’s viscosity, surface tension, and rate of evaporation during the film growth process, which in turn determined the type of pattern formed by the viruses. They also genetically engineered the virus to express specific peptides, which effect the differentiation between soft and hard tissue. "The simplicity of the technique bodes well for adapting it for use in manufacturing." said Chung, one of the lead researchers.

I found this article interesting because it is one more example of the utility of nature's efficiency in biosynthesis and bioengineering. The researchers at UC Berkeley are also acknowledging the immense effect that mechanical phenomena in the synthesis can play on the chemical and physical properties of the rendered synthetic biomedical materials. These are two of the quickly emerging themes I've seen since beginning biomedical engineering classes here at Texas A&M, and it is refreshing and encouraging to see any real-world example of them.

Electrically Spun Fabric Offers Dual Defense Against Pregnancy, HIV

Article here.

University of Washington researchers have discovered a new possible material as contraceptive and sexually transmitted infection protection that dissolves within the body.  Newly synthesized electrospun fibers deliver drugs inside the vagina during intercourse while physically blocking sperm access.  The fibers are made with an electric field to put a charged fluid through air to create fine, nanometer fibers.  The fiber’s solubility can be changed, which brings in the drug release aspect of the fiber design and synthesis.  The development of these polymers has been approved by the Food and Drug Administration.  The polymers themselves come in different forms; they can stay in the vagina up until they dissolve.  Some stay dissolve in days, and others dissolve in minutes.  Mixed fiber fabric also can release drugs at different times, increasing potency and long-term effectiveness.  This is the first developmental study using nanofibers for vaginal drug delivery and is believed to be more discrete than the condom.
I chose this article because we just finished learning about reproductive health and common contraceptive methods in class, and this research combines biomaterials, drug release, and reproductive health.  I had never considered biomedical engineering being involved with reproductive health; I was surprised upon reading this.  As research continues, the team will experiment with different combinations that treat HIV and a common contraceptive.  I was really impressed with how the team is looking to design a biomaterial that both inhibit pregnancy and STIs.

Progress for Paraplegics

View the link here:

http://www.caltech.edu/content/progress-paraplegics

The above article discusses a recent discovery made by biomedical researchers at Caltech.  Scientists had previously developed a system which allowed paraplegics to stand and even take steps on their own.  Now, a new innovation by Caltech professors Burdick, Hayman, and Tai will allow a computer interface between the patient and their electrical stimulation, and using a complex algorithm, the best pattern of electrical stimulation can be determined and applied to the patient.  This allows for optimum stimulation of the paraplegic patient, and saves the engineers a huge amount of time in terms of optimization of the array of electrotrodes.  So far, the system has already been successful in a handful of clients, and the team of engineers who developed this potentially life-changing system hope that it will be applied and used for physical therapy across the country.  While it is noted that there is no, "silver bullet," for solving paralysis, this is a large step forward in a field which was previously slow to the uptake.

This article was interesting to me because it combines prosthetics with advanced computer algorithms, and represents a significant step forward in the prosthetics world, since many new prosthetics incorporate electronic components.  I hope to work in a field similar to this some day.

Touch-Sensitive Plastic Skin Heals Itself


Chemists and engineers at Stanford created the first synthetic material that is sensitive to touch and capable of healing itself quickly and repeatedly at room temperature.  This advance in technology can lead to smarter prosthetics.  Our skin sends brain precise information about pressure and temperature and can heal efficiently to preserve a protective barrier against the world.  Within the last year, there have been extraordinary advances in synthetic skin which have had success in self healing, but have come with some drawbacks.  Some drawbacks include that some had to be exposed to high temperatures (making them impractical for day-to-day use), some could heal at room temperature, but repairing a cut changed their mechanical or chemical structure, so they could heal themselves only once. Most important, no self-healing material was a good bulk conductor of electricity, which is a crucial property. 
Researchers at Stanford were able to get “the best of both worlds” by combining the self-healing ability of a plastic polymer and the conductivity of a metal. They began with a plastic consisting of long molecular chain joined by hydrogen bonds. These hydrogen bonds allow the material to self-heal. The molecules easily break apart, but then when they reconnect, the bonds reorganize themselves and restore the structure of the material.  The result of this reorganization is a bendable material. Researchers then added tiny particle of nickel to this resilient polymer. The added nickel increased its mechanical strength. The nanoscale surfaces of the nickel particles are rough, which proved important in making the material conductive. Then the researchers took a thin strip of the material and cut it in half with a scalpel to see how well the material could restore both its mechanical strength and its electrical conductivity after damage. After pressing the pieces together the material gained back 75 percent of its original strength and electrical conductivity. Another interesting result was that the same sample could be cut repeatedly in the same place. After 50 cuts and repairs, the sample withstood bending and stretching just like the original. Researchers found that even though nickel was key to making the material strong and conductive, it also got in the way of the healing process by preventing the hydrogen bonds from reconnecting as well as they should. Researchers suggested for future that they might adjust the size and shape of the nanoparticles, or even the chemical properties of the polymer. Researchers also tested the material as a sensor. Twisting or putting pressure on the synthetic skin changes the distance between the nickel particles which allow the electrons to move with ease. The material is sensitive enough to detect the pressure of a handshake. The material is sensitive not only to downward pressure but also to flexing, so a prosthetic limb might someday be able to register the degree of bend in a joint.
I found this article interesting because I hope to one day work with prosthetic engineering. I find the advances in research and technology that can impact prosthetic devices truly amazing and astounding. I feel that the possibilities for this type of research are endless. Unfortunately, there will always be a demand for prosthetics, so the possibility of giving a person an artificial limb that can’t replace what they lost, but help them lead a full life with no drawbacks.


Molecular Knock-Out Alleviates Alzheimer's Symptoms in Mice

http://www.sciencedaily.com/releases/2012/11/121130121600.htm
Researches in the department of Psychiatry and Psychotherapy at the University Medical Center Gottingen and investigated mice that showed behavioral disorders and brain deposits that are typically associated with Alzheimer's disease. They removed genes responsible for the HDAC6 enzyme. The mice exhibited the pathological features of Alzheimer's disease, but removal of these genes improved their behavior. The mice were had a better grasp on being able to find and learn their spatial bearings while having normal cognitive abilities. This behavior happened because transport processes within nerve cells are facilitated when HDAC6 is not around.  Cell transport becomes functional with the removal of this gene. This gene is a possible target for therapies against Alzheimer's, but in humans, there would need to be a treatment to disable the enzyme.  The goal is to figure out what treatment or drug is necessary to disable HDAC6.

I believe this is such a huge step in Alzeimer's Research.  For so long, there has been no known cure for Alzheimer's and I think it is really cool that they have finally linked this awful disease to a gene and enzyme.  My grandfather has Alzeimer's and to know that if he continues to battle it that in the near future there might be some hope for him.  I would love to know the research they do on the further treatment and what their plans for that are. I would also love to see the results and what they come up with in finding a blocker on this enzyme.

Nano propeller

Link here. *Watch the video that is linked right under the second paragraph*

Ambarish Ghosh and Peer Fischer are researchers at the University of Harvard who have designed a nanopropeller. This nanopropeller is 2 microns long and 200-300 nm wide, making it about the size of a bacterial cell. It is made out of glass and is shaped like a corkscrew. This glass is then magnetized so that the propeller can be controlled by the researchers. Some nanopropellers have been made before but this is the first one that can be completely controlled and manipulated while it is in solution. The control system is so sensitive that the researchers were able to trace the letters "R @ H" to represent Rowland at Harvard in a window that's width is less than the width of a human hair. The researchers are also able to control two of the propellers simultaneously. One nanopropeller can move an object that is 1000 times bigger than the propeller itself with ease.

You can make hundreds of millions of nanopropellers in a square centimeter. The nanopropellers are made by exposing a silicon wafer to silicon dioxide vapor. the wafer is slowly spun as the vapor solidifies to create the corkscrew and then the nanopropellers are shaken off the wafer, sprayed with cobalt, and magnetized. The cobalt only goes on one side of the propeller so it creates the perfect handle for controlling their movement.

In order to control the propellers, they are placed in a solution that is surrounded by 3 magnetic coils, one on each axis. This gives the researchers precise control over the actions and movements of the nanopropellers. The propellers can move at a speed of 40 microns per second, about the average speed of a bacteria. It isn't any faster than that because when you get down to such a small level, moving through water becomes more viscous due to the surface area to volume ratio so the propeller has to drill through the water solution in order to move.

I choose this article because it can have many effects on future nano robot technology and it can help with drug delivery and microsurgery one day.


Telomeres and death

The article I read discuesses the the effects of having short telomeres are. We know that short telomeres get smaller as a person gets older and that some diseases are linked to having shorter telomeres. The researchers in this article wanted to see if there was a link between short telomeres and poor health.  Researchers at the University of California measured the telomere length in 110,266 people. This study is still on going. They did discover that when the telomeres get critically short, the chances of an individual dying increase. The death risk is equivalent to "people who drink 20 to 30 alcoholic beverages per week." The research study did confirm that as a person ages their telomeres get shorter. They study also noted that men over 75 and women over 80 tended to have longer telomeres than people who were younger and died. The researches believe that the telomeres don't actually get longer when you get into old age but rather those individuals died who had shorter telomeres. It was found that people who smoked or drank heavily were more likely to have shorter telomeres, and higher levels of education were associated with longer telomeres. The study is still going and more data needs to be collected.

The reason I found this article interesting is because it shows another sign to living longer or dying earlier. It shows how small and simple molecules can have such a great affect on humans. It also relates to how everything in the human body is a produced a certain way and the lengths of telomeres can have such a great impact on humans. Another reason I found this article interesting was because what the researchers found also correlates to what another group of researchers found in birds. Birds with shorter or trunacated telomeres had a greater chance of dying. Possible more research done on the birds could help improve our understanding on our own physiology.

Article
Bird Article

Thursday, November 29, 2012

New Strategy to Fix a Broken Heart: Scaffold Supports Stem Cell-Derived Cardiac Muscle Cells




Scientists at the University of Washington have created a heart scaffold that allows for angiogenesis and the proliferation of cardiac tissue in vivo.  The scaffold has been tested on rats and chickens proving its effectiveness.  Four weeks after implantation, both the rat and chicken bodies had accepted the scaffold and blood vessels had traveled deep into the scaffold.  UW scientists believe, eventually, the scaffold could be injected into the heart to help heal tissue damage before scar tissue forms.  They also believe the scaffold could potentially be able to generate a brand new heart in vitro.

This article interested me, because, up until now I was under the impression complex organs were too difficult to currently create with scaffolds due to their multifunctionality and their makeup of diverse cell types.  Although it will be some time before a human-safe scaffold is created, it is definitely something to look forward to and I believe it will happen within our generation given the rate of technological advancements in just the past decade.