http://www.guardian.co.uk/science/2008/aug/06/genetics.korea
Future applications can be used for this field
Tuesday, August 5, 2008
Friday, August 1, 2008
German doctors have carried out a complete double arm transplant.
The patient was a 54-year-old farmer who lost his limbs in an accident six years ago.
The donor is believed to be a teenager who had died shortly before the surgery. Neither man's name has been released by the Munich clinic.
The 15-hour operation took place last week, and the patient is recovering well, though it could be two years before he can move his new hands.
Arm transplants have been carried out before - the first occurred in Austria in 2003 when a man received transplanted forearms and hands.
In this procedure, limbs were reattached just below the shoulder.
Reiner Gradinger, medical director at the Munich University Clinic where the operation involving 40 doctors, nurses and assistants took place over 15 hours last week, said: "The reattachment appears up to now to have proceeded optimally."
Surgeon Edgar Biemer said the greatest challenge was establishing blood flow between the farmer's body and muscles in the new arms because the muscles have a limited lifespan.
And he said: "We discussed with the patient that he would have to deal with the fact that his hands were from somebody else.
"But this was discussed before the first heart transplant, and in reality nobody really cared about that."
Doctors are monitoring the patient closely to make sure his body does not reject the new limbs.
Long wait
The patient cannot move his new arms but doctors hope his network of nerves will expand at a pace of around one millimetre (0.04 inches) per day.
Even if that happens, it could still be two years before the patient can manipulate his new hands.
Hans-Guenther Machens, director of hand and plastic surgery at the clinic, said: "The regeneration process will take a long time."
UK transplant expert Nadey Hakim, head of the transplant unit at London's Hammersmith Hospital, said the higher up an amputation on the arms, the easier it was to connect new limbs, as there were fewer nerves and only one bone to connect.
But he added: "It is going to be quite difficult to get any sensation. The higher it is, the harder it is.
"Flexing and bending the arm is also going to be hard."
"He is going to require intensive physiotherapy every day for many months."
The donor is believed to be a teenager who had died shortly before the surgery. Neither man's name has been released by the Munich clinic.
The 15-hour operation took place last week, and the patient is recovering well, though it could be two years before he can move his new hands.
Arm transplants have been carried out before - the first occurred in Austria in 2003 when a man received transplanted forearms and hands.
In this procedure, limbs were reattached just below the shoulder.
Reiner Gradinger, medical director at the Munich University Clinic where the operation involving 40 doctors, nurses and assistants took place over 15 hours last week, said: "The reattachment appears up to now to have proceeded optimally."
Surgeon Edgar Biemer said the greatest challenge was establishing blood flow between the farmer's body and muscles in the new arms because the muscles have a limited lifespan.
And he said: "We discussed with the patient that he would have to deal with the fact that his hands were from somebody else.
"But this was discussed before the first heart transplant, and in reality nobody really cared about that."
Doctors are monitoring the patient closely to make sure his body does not reject the new limbs.
Long wait
The patient cannot move his new arms but doctors hope his network of nerves will expand at a pace of around one millimetre (0.04 inches) per day.
Even if that happens, it could still be two years before the patient can manipulate his new hands.
Hans-Guenther Machens, director of hand and plastic surgery at the clinic, said: "The regeneration process will take a long time."
UK transplant expert Nadey Hakim, head of the transplant unit at London's Hammersmith Hospital, said the higher up an amputation on the arms, the easier it was to connect new limbs, as there were fewer nerves and only one bone to connect.
But he added: "It is going to be quite difficult to get any sensation. The higher it is, the harder it is.
"Flexing and bending the arm is also going to be hard."
"He is going to require intensive physiotherapy every day for many months."
Thursday, July 31, 2008
Exercise in a Pill
July 31, 2008 -- It may be possible to make a pill that captures the endurance-boosting effects of exercise, scientists report in Cell.
So far, they've tested two compounds in lab tests in mice. One of those compounds, called GW1516, boosted endurance in mice that exercised, but not in sedentary mice. The other compound, called AICAR, improved endurance in mice that didn't exercise at all.
Those compounds haven't yet been tested in people, and they're not on the market. But the researchers are already working on a drug test to screen for traces of GW1516 and AICAR in athletes' blood and urine.
Here's a quick look at the two compounds.
Back in 2004, the researchers -- who included professor Ronald M. Evans, PhD, of the Salk Institute for Biological Studies and the Howard Hughes Medical Institute in La Jolla, Calif. -- reported that they boosted endurance in mice by tweaking a mouse gene to boost the activity of a protein called PPAR-delta.
Evans' team then worked on getting the same result without genetic engineering. They squirted GW1516, which boosts PPAR-delta, into mice's mouths every day for a month.
At the end of the month, the mice ran 68% longer and 70% farther than when the experiment began -- but only if they had been running on exercise wheels daily while taking the drug. GW1516 didn't do anything for mice that weren't exercising.
Next, the scientists focused on another protein called AMPK. They gave sedentary mice a daily injection of AICAR, which boosts AMPK, for a month.
At the end of the month, those mice ran 23% longer and 44% farther than before starting AICAR treatment. That is, their endurance had improved without working out.
The results show that AMPK and PPAR-delta "can be targeted by orally active drugs to enhance training or even to increase endurance without exercise," write the researchers.
The mouse tests were all about skeletal muscles and endurance, not about the drugs' safety or ability to mimic the many other benefits of exercise, such as improving cardiovascular health and making some types of cancer less likely.
So far, they've tested two compounds in lab tests in mice. One of those compounds, called GW1516, boosted endurance in mice that exercised, but not in sedentary mice. The other compound, called AICAR, improved endurance in mice that didn't exercise at all.
Those compounds haven't yet been tested in people, and they're not on the market. But the researchers are already working on a drug test to screen for traces of GW1516 and AICAR in athletes' blood and urine.
Here's a quick look at the two compounds.
Back in 2004, the researchers -- who included professor Ronald M. Evans, PhD, of the Salk Institute for Biological Studies and the Howard Hughes Medical Institute in La Jolla, Calif. -- reported that they boosted endurance in mice by tweaking a mouse gene to boost the activity of a protein called PPAR-delta.
Evans' team then worked on getting the same result without genetic engineering. They squirted GW1516, which boosts PPAR-delta, into mice's mouths every day for a month.
At the end of the month, the mice ran 68% longer and 70% farther than when the experiment began -- but only if they had been running on exercise wheels daily while taking the drug. GW1516 didn't do anything for mice that weren't exercising.
Next, the scientists focused on another protein called AMPK. They gave sedentary mice a daily injection of AICAR, which boosts AMPK, for a month.
At the end of the month, those mice ran 23% longer and 44% farther than before starting AICAR treatment. That is, their endurance had improved without working out.
The results show that AMPK and PPAR-delta "can be targeted by orally active drugs to enhance training or even to increase endurance without exercise," write the researchers.
The mouse tests were all about skeletal muscles and endurance, not about the drugs' safety or ability to mimic the many other benefits of exercise, such as improving cardiovascular health and making some types of cancer less likely.
Bone Tissue Engineering
Bone tissue engineering is a rapidly developing area. This form of therapy differs from standard drug therapy or permanent implants in that the engineered bone becomes integrated within the patient, affording a potentially permanent and specific cure of the disease state. The problem with putting man-made materials in the body is that they are subject to fatigue, fracture, toxicity, and wear, and do not remodel with time. In tissue engineering for the bones, you make the cells in a culture and then place them into the patient. Cells in the body are constantly receiving mechanical, electrical, structural and chemical cues to what they should be doing. So it is important to place the cell in back into the body so that can get the cures so go in the shape and form that they are needed to be in. Bone tissue engineering can possibly for a substitute in the bone instead of using man made materials.
Bioengineered external heart
Earlier this year tissue engineers at the University of Minnesota have created the first externally engineered heart. They stripped a rat’s heart of its own cells using a kind of bleach solution. Afterwards they infused the adult rat heart cells with that of a newborn rat. This takes quite a bit of time and skill but many of the scientists argee that this is a landmark in the field of tissue engineering. Being able to engineer organs could one day result in the making of biocompatible transplant organs for patients. We are nowhere near this point right now but it is still a field of research that deserves much attention.
There are many challenges in created a working heart for humans in an external environment. First of all the heart muscle is very thick and tissue engineers have not found a way yet to ensure that enough oxygen gets to the inner layers of the heart muscle. That and creating the necessary scaffolding for a three dimensional structure is on the top of the list of major problems. The easiest part about the project is that for heart cells you don’t have to tell them to beat in synchrony because they already know to do that.
Many of the researchers at the University of Minnesota are very optimistic and hope to have a working human heart and hopefully other organs such kidneys, livers, and lungs. They wish to have at least a working one of these within 15 years. These are very optimistic propositions but nonetheless it has been a great achievement in the biomedical industry.
http://www.startribune.com/lifestyle/health/13751901.html
Sources and Cool Article
Here's my sources:
http://www.cbte.group.shef.ac.uk/research/te5.html
http://www.innovations-report.com/html/reports/medicine_health/report-42576.html
http://www.jhu.edu/JLAB/Projects/Cornea.html
And here's a cool article about sweat glands functioning as antennaes:
http://physicsworld.com/cws/article/news/33704
(The link may not work unless you make an account on their site)
http://www.cbte.group.shef.ac.uk/research/te5.html
http://www.innovations-report.com/html/reports/medicine_health/report-42576.html
http://www.jhu.edu/JLAB/Projects/Cornea.html
And here's a cool article about sweat glands functioning as antennaes:
http://physicsworld.com/cws/article/news/33704
(The link may not work unless you make an account on their site)
Corneal Tissue Engineering
Due to the fragility of the eye, a 5-30% rejection rate for donor eyes, and the complexity of creating a transducer to send image data to the brain, corneal tissue engineering is a more friendly approach to a persistent problem; how to return site to those who have lost it due to disease or damage to the eye, or in this particular case, the cornea. Currently, corneal epithelial cells from other, healthy donors can be succesfully cultured and prepared for placement on the cornea. However, these donor epithelial cells are often rejected, and a patient wanting to undergo this treatment must take immunosuppressants (though in the distant future, healthy epithelial cells might be able to be genetically engineered from the patients own epithelial cells, preventing acceptance problems). There are also significant problems with attaching these epithelial cells to the damaged cornea. Currently this area is undergoing the most thorough investigation, resulting in a variety of different methods. The most common method is to use a human amniotic membrane as a hub to which all the epithelial cells can attach, and then to suture this onto the cornea. But this method requires an amniotic membrane donor, making supply and issue two major issues. There is also a proposed method of engineering a contact lense capable of transfering the epithelial cells to the damaged sections of the cornea, which requires an acrylic acid coating on the contact lense. However, engineering a suitable contact lense requires extensive knowlege of both organ culture and surface chemical engineering, making the construction a very complex process.
Tissue Engineered Bladder
For patients with bladder disease, one of the only treatment options was the replacement of bladder tissue with intestinal tissue. Side effects of that procedure include colon cancer and infection, because the intestinal tissue is designed to absorb water rather than release water. Another option is to tissue-engineer a new bladder from cells. At Wake Forest University, doctors took a biopsy of the bladder and seeded the cells into a scaffold made of synthetic polymer. The synthetic polymer scaffold is designed to fit the patient and mimic the collagen that exists in the natural bladder. After seven weeks in an incubator, the cells colonized and the bladder was implanted about the existing bladder, where it would continue to grow and improve existing bladder function. While the procedure is still experimental and cannot repair nerve damage, it tremendously improves the lives of bladder disease patients.
Sources:
http://www.washingtonpost.com/wp-dyn/content/article/2006/04/03/AR2006040301387.html
http://news.healingwell.com/index.php?p=news1&id=531931
Sources:
http://www.washingtonpost.com/wp-dyn/content/article/2006/04/03/AR2006040301387.html
http://news.healingwell.com/index.php?p=news1&id=531931
Artificial Blood
Eric Shine
Engineering Biomedical Systems
July 31, 2008
Artificial Blood
Tissue engineering is a broad field of engineering that deals with a combination of cells, and engineering methods that are used to improve of replace biological functions. An application of tissue that could help improves or replaces biological functioning would be the creation of artificial blood. Blood is a very complicated tissue. Blood contains two main components plasma and the formed elements. To add further complexity the formed elements are made up of RBCs (red blood cells), WBCs (white blood cells), and platelets. Along with blood being the transportation system of the body, blood comes in four different types: A, B, AB, and O. Since blood Artificial blood would help traumatic brain injuries, which is a leading cause in accidental death. Even though blood is very complex engineers and scientist have made a type of artificial blood called Oxycyte. Oxycyte is a revolutionary artificial blood because it can carry 50 times more oxygen than human blood. This synthetic blood is step in making blood transfusions and other types of blood related problems a thing of the past.
http://www.popsci.com/scitech/article/2006-11/better-blood
http://health.howstuffworks.com/artificial-blood1.htm
http://en.wikipedia.org/wiki/Tissue_engineering#Examples_of_tissue_engineering_technologies
Engineering Biomedical Systems
July 31, 2008
Artificial Blood
Tissue engineering is a broad field of engineering that deals with a combination of cells, and engineering methods that are used to improve of replace biological functions. An application of tissue that could help improves or replaces biological functioning would be the creation of artificial blood. Blood is a very complicated tissue. Blood contains two main components plasma and the formed elements. To add further complexity the formed elements are made up of RBCs (red blood cells), WBCs (white blood cells), and platelets. Along with blood being the transportation system of the body, blood comes in four different types: A, B, AB, and O. Since blood Artificial blood would help traumatic brain injuries, which is a leading cause in accidental death. Even though blood is very complex engineers and scientist have made a type of artificial blood called Oxycyte. Oxycyte is a revolutionary artificial blood because it can carry 50 times more oxygen than human blood. This synthetic blood is step in making blood transfusions and other types of blood related problems a thing of the past.
http://www.popsci.com/scitech/article/2006-11/better-blood
http://health.howstuffworks.com/artificial-blood1.htm
http://en.wikipedia.org/wiki/Tissue_engineering#Examples_of_tissue_engineering_technologies
An Artificial Pancreas
Diabetes is a physically as well as mentally and emotionally devastating disease. The inability of the pancreas to efficiently produce insulin lies at the root of the diabetic problem. There are machines and pumps available today for sufferers of diabetes to track their blood glucose levels and to regulate their insulin, but the process creates constant discomfort and worry for the patient.
Tissue engineers, in their efforts, are trying to create the perfect combination of comfort and insulin production through the invention of an artificial pancreas. This artificial pancreas would be able to automatically adjust the insulin levels for a diabetic patient. It would also restore normal endocrine functionality.
The complete development and use of an artificial pancreas would improve the insulin therapy to the point at which physiological complications cease. Variations of this artificial pancreas idea have arisen among the sciences. Among them are the biomedical device ideas to implant an insulin pump that would assume the role of the pancreas, a bioartificial pancreas made of a biocompatible sheet of "encapsulated beta cells" (Wikipedia), and the use of gene therapy to convert digestive cells into insulin producing cells.
All of these projects have the common goal of creating a normal pancreas function, artificial or not, in the body. One of the benefits of tissue engineering is its more natural approach to the replacement of diseased tissues in the body.
Tissue engineers, in their efforts, are trying to create the perfect combination of comfort and insulin production through the invention of an artificial pancreas. This artificial pancreas would be able to automatically adjust the insulin levels for a diabetic patient. It would also restore normal endocrine functionality.
The complete development and use of an artificial pancreas would improve the insulin therapy to the point at which physiological complications cease. Variations of this artificial pancreas idea have arisen among the sciences. Among them are the biomedical device ideas to implant an insulin pump that would assume the role of the pancreas, a bioartificial pancreas made of a biocompatible sheet of "encapsulated beta cells" (Wikipedia), and the use of gene therapy to convert digestive cells into insulin producing cells.
All of these projects have the common goal of creating a normal pancreas function, artificial or not, in the body. One of the benefits of tissue engineering is its more natural approach to the replacement of diseased tissues in the body.
Testing Drugs with Stem Cells
Stem cells have many applications now, and there are many more that are still being developed. However, one such use of stem cells that has already been established is the use of stem cells in testing the toxicity of pharmaceutical drugs.
Previously, drugs were tested in rats before they were administered to humans. This process is somewhat flawed in that drugs have been known to act differently in humans that in the lab animals that they were previously tested on. So, a woman named Gabriella Cezar came up with a way of using embryonic stem cells to test drug toxicity. She exposed these stem cells to the drug that was being tested and then let them react. These stem cells react with drugs like a human would, eliminating the chance of poisoning a human by accident. These stem cells produce a molecule that help metabolism. Cezar hypothesized that if the drug were toxic, then there would be different amounts of that metabolic compound in the stem cells than normally.
Cezar ran another test with valproate, a drug supposed to help and epileptic patient, which has been linked with causing autism. Cezar gave different dosages to different samples of stem cells while keeping some control groups to compare to. She found that the stem cell environments with the most valproate produced the most glutamate and kynurenin; both are used in brain development.
Even though this method of using stem cells is not an exact science yet, it is up and coming application of stem cells.
Heart in a Jar
Tissue engineering's whole purpose is to replace biological functions with new cell material products. Mostly, tissue engineers try to repair portions of organs that have been damaged. However, earlier this year, Doris Taylor made medical history by creating an entirely new rat heart in a lab. This beating heart was made by leaving only nonliving matrix of the rat's heart and redesigning it with new heart cells. To first remove all the cells to get to the matrix, detergents were pumped throughout the organ to wash away the debris in the network of blood vessels. This left the extracellular matrix or ECM as a matrix of protein fibers that create the connective tissue in the heart. This ECM was basically a skeleton of the organ's 3-D structure that was then formed into a heart with new cells. These cells were a mix of stem and progenitor cells from newborn rats that were injected into the left ventricle of the ECM. After pumping nutrients and oxygen throughout the heart and its blood vessels, four days later the heart starting contracting. The heart was then stimulated by electrodes to synchronize the beats. Taylor is continuing her study with experimenting with pig hearts and their own ECM. The hope is that one day new hearts will be creating for the 5 million people living with heart failure. This new advancement in tissue engineering could someday make organ transplants obsolete.
http://en.wikipedia.org/wiki/Doris_Taylor
http://www1.umn.edu/umnnews/Feature_Stories/Researchers_create_a_new_heart_in_the_lab.html
http://en.wikipedia.org/wiki/Doris_Taylor
http://www1.umn.edu/umnnews/Feature_Stories/Researchers_create_a_new_heart_in_the_lab.html
Gene Therapy
Gene therapy is a form of treatment that doctors and scientists hope to use against genetic diseases. Instead of battling a foreign body, which is not the source of problems in genetic diseases, the goal in gene therapy is to replace faulty genes causing illness in patients with correct ones. What one uses to replace the old gene with the new one is called a vector. There are many different vectors for placement of new genes, such as using viruses, naked-DNA injection, dendrimers, and others.
The first approved gene therapy procedure was performed in 1990. It was meant to treat severe combined immunodeficiency, or SCID, a genetic disease in which certain receptors on white blood cells are not correctly coded for in the corresponding gene, rendering white blood cells useless. Doctors removed white blood cells from the patient, a four year old girl, let the cells develop in cultures, then inserted the correct gene into the cells and put the cells back into the patient. Even though the procedure only lasted a couple months, it boosted the patient's immune system so much that she could now attend school, which she previously couldn't do due to her extremely high risk of fatal infections from what are considered mundane conditions, such as colds. This case shows promise for gene therapy, even if results aren't permanent.
http://en.wikipedia.org/wiki/Gene_therapy
http://en.wikipedia.org/wiki/Severe_combined_immunodeficiency
The first approved gene therapy procedure was performed in 1990. It was meant to treat severe combined immunodeficiency, or SCID, a genetic disease in which certain receptors on white blood cells are not correctly coded for in the corresponding gene, rendering white blood cells useless. Doctors removed white blood cells from the patient, a four year old girl, let the cells develop in cultures, then inserted the correct gene into the cells and put the cells back into the patient. Even though the procedure only lasted a couple months, it boosted the patient's immune system so much that she could now attend school, which she previously couldn't do due to her extremely high risk of fatal infections from what are considered mundane conditions, such as colds. This case shows promise for gene therapy, even if results aren't permanent.
http://en.wikipedia.org/wiki/Gene_therapy
http://en.wikipedia.org/wiki/Severe_combined_immunodeficiency
Wednesday, July 30, 2008
Bioartificial Liver Devices
One tissue engineering device is the Bioartificial Liver Device (BAL). There are two BAL's currently in clinical trials, they are the HepatAssist 2000 and the ELAD. The aim of both of these devices is either as a bridge to transplant, or as a means of letting the liver regenerate on it's own. Both perform these tasks rather well, but both differ in the method used to do this.
The HepatAssist 2000 is an extracorporeal device with hollow tubes and pig liver tissue samples that filters the plasma. This is good as plasma has a better flow rate, there is a greater molecular transfer rate, and there is decreased intracranial pressure. The down side is that pig cells create pig proteins which may cause immune responses, the plasma separation process can also cause problems.
The ELAD uses filtration cartridges much like kidney dialysis. These tubes contained hollow fibers with cloned human cells that are cultured in them. The ELAD is good as it mimics many of the natural liver functions like metabolizing amino acids and producing proteins and clotting factors. The down side of this product could be the fact that it doesn't have the better flow rates that the HepatAssist 2000 has.
http://www.medscape.com/viewarticle/420583
The HepatAssist 2000 is an extracorporeal device with hollow tubes and pig liver tissue samples that filters the plasma. This is good as plasma has a better flow rate, there is a greater molecular transfer rate, and there is decreased intracranial pressure. The down side is that pig cells create pig proteins which may cause immune responses, the plasma separation process can also cause problems.
The ELAD uses filtration cartridges much like kidney dialysis. These tubes contained hollow fibers with cloned human cells that are cultured in them. The ELAD is good as it mimics many of the natural liver functions like metabolizing amino acids and producing proteins and clotting factors. The down side of this product could be the fact that it doesn't have the better flow rates that the HepatAssist 2000 has.
http://www.medscape.com/viewarticle/420583
Gene Therapy
Genes, which are carried on chromosomes, are the basic physical and functional units of heredity. Genes are specific sequences of bases that encode instructions on how to make proteins. Although genes get a lot of attention, it’s the proteins that perform most life functions and even make up the majority of cellular structures. When genes are altered so that the encoded proteins are unable to carry out their normal functions, genetic disorders can result. Gene therapy is a technique for correcting defective genes responsible for disease development. Researchers use several approaches for correcting faulty genes including:
· inserting a normal gene into a nonspecific location within the genome to replace a nonfunctional gene
· swapping an abnormal gene for a normal gene through homologous recombination
· repairing the abnormal gene through selective reverse mutation
In most gene therapy studies, a "normal" gene is inserted into the genome to replace an "abnormal," disease-causing gene. A carrier molecule called a vector must be used to deliver the therapeutic gene to the patient's target cells. Currently, the most common vector is a virus that has been genetically altered to carry normal human DNA. Viruses have evolved a way of encapsulating and delivering their genes to human cells in a pathogenic manner. Scientists have tried to take advantage of this capability and manipulate the virus genome to remove disease-causing genes and insert therapeutic genes.
· inserting a normal gene into a nonspecific location within the genome to replace a nonfunctional gene
· swapping an abnormal gene for a normal gene through homologous recombination
· repairing the abnormal gene through selective reverse mutation
In most gene therapy studies, a "normal" gene is inserted into the genome to replace an "abnormal," disease-causing gene. A carrier molecule called a vector must be used to deliver the therapeutic gene to the patient's target cells. Currently, the most common vector is a virus that has been genetically altered to carry normal human DNA. Viruses have evolved a way of encapsulating and delivering their genes to human cells in a pathogenic manner. Scientists have tried to take advantage of this capability and manipulate the virus genome to remove disease-causing genes and insert therapeutic genes.
Stem Cells to Cure Parkinson's
Scientists have been working with stem cells since the 1980s, continuously searching to find functional benefits of the relatively new technology. In 2007 and article, “Stem Cells Make Neurons, and Tumors, in Rate Model of Parkinson’s Disease,” was released stating that “human embryonic stem cells led to dramatic functional improvement” although it was also shown to cause brain tumors. Research was done to determine whether stem cells could help cure Parkinson’s disease (PD). PD causes muscles to stiffen and a person’s movement to slow. It is believed that stem cells could help PD because it is a disease that damages few neurons which produce dopamine.
An experiment performed by Steven Goldman, M.D., Ph.D., at the University of Rochester Medical Center described how the stem cells were induced to become dopamine producing neurons. The cells were placed in rats with a condition similar to PD and the rats recovered their mobile functions. Along with the recovery, however, a tiny amount of the implanted cells had formed tumors. Stem cells had been produced in the past that showed therapeutic effects for PD, but the study was the first to show that cells derived from humans are able to produce positive effects as well as those cells derived from animals.
The study was continued with the use of a toxin that destroyed dopamine producing neurons being implanted into rats before any problems with movement existed. The rats were treated with the stem cells and showed to perform as well as rats that had not received the toxin within a few months. Dr. Goldman believes that all the team needs to do it find a way “‘to purify the neurons and separated them from the undifferentiated cells.’” The results from Dr. Goldman’s experiment are promising despite the fact that some tumors had formed on a few cells. The field of stem cell therapeutics is rapidly growing.
http://www.ninds.nih.gov/news_and_events/news_articles/stem_cells_improve_PD.htm
An experiment performed by Steven Goldman, M.D., Ph.D., at the University of Rochester Medical Center described how the stem cells were induced to become dopamine producing neurons. The cells were placed in rats with a condition similar to PD and the rats recovered their mobile functions. Along with the recovery, however, a tiny amount of the implanted cells had formed tumors. Stem cells had been produced in the past that showed therapeutic effects for PD, but the study was the first to show that cells derived from humans are able to produce positive effects as well as those cells derived from animals.
The study was continued with the use of a toxin that destroyed dopamine producing neurons being implanted into rats before any problems with movement existed. The rats were treated with the stem cells and showed to perform as well as rats that had not received the toxin within a few months. Dr. Goldman believes that all the team needs to do it find a way “‘to purify the neurons and separated them from the undifferentiated cells.’” The results from Dr. Goldman’s experiment are promising despite the fact that some tumors had formed on a few cells. The field of stem cell therapeutics is rapidly growing.
http://www.ninds.nih.gov/news_and_events/news_articles/stem_cells_improve_PD.htm
Artificial Blood Vessels
Artificial blood vessels were first introduced during WWI when Alexis Carrel discovered a way to sew blood vessels together. Today, methods from the 1940s and 1950s are still used. Surgeons originally used transplants for arteries or veins. However, this method resulted in failure. The recipient’s body either rejected the vessels or arteriosclerosis (artery hardening) formed. To transplant vessels from the same body required two complicated surgeries and most patients with circulatory problems did not have vessels for transplantation.
Researchers began to develop artificial vessels to overcome this problem. Tubing materials included polyethylene (soft and waxy plastic) and siliconized rubber. Further research proved that vessels made from Teflon and Dacron were not rejected by the body. While the larger Dacron vessels worked well, the smaller ones formulated blood clots. Smoother interior walls would help prevent clots from forming.
In the 1980s, Donald Lyman synthesized a polymer that reduced clot formation. The elastic polymer also reduced the strain where the natural and artificial valves met. Human testing began in 1988. In 1990, the bio-research company Organogenesis implanted a hybrid vessel in animals made of natural and artificial materials. This artificial vessel features a smooth inner layer grown in the laboratory from human cadaver (dead body) artery cells and tubules strengthened with Dacron mesh. Stuart Williams at Jefferson Medical College, Philadelphia, Pennsylvania, uses cells from the patient's own inner blood vessel lining to grow a lining on the inside of Dacron synthetic vessels.
Researchers have already managed to make wider blood vessels from scratch, but the formation of the tiny diameter capillaries needed to create a blood supply within other tissues and organs is more challenging. However, through the “nanoscale” template, US scientists claim to have made progress using stem cells using endothelial progenitor. These cells detect the grooves and align themselves in the direction of the vessel. When a gel is added, the cells grow outward consequently forming tiny tubes. Even though these tubes are not ready to be placed inside the body, researchers cannot contain their enthusiasm for the potential results of this process.
http://www.discoveriesinmedicine.com/Apg-Ban/Artificial-Blood-Vessels.html
http://news.bbc.co.uk/2/hi/health/7152405.stm
Researchers began to develop artificial vessels to overcome this problem. Tubing materials included polyethylene (soft and waxy plastic) and siliconized rubber. Further research proved that vessels made from Teflon and Dacron were not rejected by the body. While the larger Dacron vessels worked well, the smaller ones formulated blood clots. Smoother interior walls would help prevent clots from forming.
In the 1980s, Donald Lyman synthesized a polymer that reduced clot formation. The elastic polymer also reduced the strain where the natural and artificial valves met. Human testing began in 1988. In 1990, the bio-research company Organogenesis implanted a hybrid vessel in animals made of natural and artificial materials. This artificial vessel features a smooth inner layer grown in the laboratory from human cadaver (dead body) artery cells and tubules strengthened with Dacron mesh. Stuart Williams at Jefferson Medical College, Philadelphia, Pennsylvania, uses cells from the patient's own inner blood vessel lining to grow a lining on the inside of Dacron synthetic vessels.
Researchers have already managed to make wider blood vessels from scratch, but the formation of the tiny diameter capillaries needed to create a blood supply within other tissues and organs is more challenging. However, through the “nanoscale” template, US scientists claim to have made progress using stem cells using endothelial progenitor. These cells detect the grooves and align themselves in the direction of the vessel. When a gel is added, the cells grow outward consequently forming tiny tubes. Even though these tubes are not ready to be placed inside the body, researchers cannot contain their enthusiasm for the potential results of this process.
http://www.discoveriesinmedicine.com/Apg-Ban/Artificial-Blood-Vessels.html
http://news.bbc.co.uk/2/hi/health/7152405.stm
Use of Gene Therapy for Dwarfism
Alexis Gorin
Farah Laiwalla
Engineering Biomedical Systems (BI920-3B)
Wednesday, July 30, 2008
To treat dwarfism, the condition of abnormally-caused small stature, doctors use gene therapy as an option to help people affected, using growth hormone and any other hormone the person may be missing. The amount of each type of hormone given constantly changes though due to (metabolic) changes within the child (1).
Different drug deliveries systems are used to get the growth hormone in the body systems. One way, used by doctors like Jeffery M. Leiden, is to remove muscle cells and place the gene that makes HGH inside the cells, only to be placed back inside the body (2). This method has become very effective since new research came out, proving that muscle cells can secrete proteins. The study shows that after three months, the mice the manipulated muscle cells were put in were still making HGH.
Another way to deliver the needed hormones, although can be used for other purposes, is to put the hormone-creating gene into "replication-deficient retrovirus" (3). The virus then can attach to muscle cells and has its host cell copy the hormone-creating genetic material, have the material build up, and then spread to other cells. This was created by Vandenburgh as a way to deal without constant injections of proteins.
(1) "Dwarfism." Free Health Encyclopedia. 2007. NetIndustries, LLC. . 30 Jul 2008 http://www.faqs.org/health/topics/99/Dwarfism.html.
(2) Angier, Natalie. "With Direct Injections, Gene Therapy Takes A Step Into a New Age ." The New York Times 14 April 1992 30 Jul 2008 http://query.nytimes.com/gst/fullpage.html?res=9E0CE6DB1E3BF937A25757C0A964958260&sec=&spon=&pagewanted=all.
(3) "Gene Therapy - Putting Muscle Into the Research." NASA. 06 June 2002. NASA. 30 Jul 2008 http://www.nasa.gov/vision/earth/livingthings/gene_therapy_prt.htm.
Farah Laiwalla
Engineering Biomedical Systems (BI920-3B)
Wednesday, July 30, 2008
To treat dwarfism, the condition of abnormally-caused small stature, doctors use gene therapy as an option to help people affected, using growth hormone and any other hormone the person may be missing. The amount of each type of hormone given constantly changes though due to (metabolic) changes within the child (1).
Different drug deliveries systems are used to get the growth hormone in the body systems. One way, used by doctors like Jeffery M. Leiden, is to remove muscle cells and place the gene that makes HGH inside the cells, only to be placed back inside the body (2). This method has become very effective since new research came out, proving that muscle cells can secrete proteins. The study shows that after three months, the mice the manipulated muscle cells were put in were still making HGH.
Another way to deliver the needed hormones, although can be used for other purposes, is to put the hormone-creating gene into "replication-deficient retrovirus" (3). The virus then can attach to muscle cells and has its host cell copy the hormone-creating genetic material, have the material build up, and then spread to other cells. This was created by Vandenburgh as a way to deal without constant injections of proteins.
(1) "Dwarfism." Free Health Encyclopedia. 2007. NetIndustries, LLC. . 30 Jul 2008 http://www.faqs.org/health/topics/99/Dwarfism.html.
(2) Angier, Natalie. "With Direct Injections, Gene Therapy Takes A Step Into a New Age ." The New York Times 14 April 1992 30 Jul 2008 http://query.nytimes.com/gst/fullpage.html?res=9E0CE6DB1E3BF937A25757C0A964958260&sec=&spon=&pagewanted=all.
(3) "Gene Therapy - Putting Muscle Into the Research." NASA. 06 June 2002. NASA. 30 Jul 2008 http://www.nasa.gov/vision/earth/livingthings/gene_therapy_prt.htm.
Bone Scaffolds
Marissa Reitsma
7/30/08
Bone Scaffolds
http://www.acfnewsource.org/science/bone_scaffold.html
http://www.rsc.org/Publishing/Journals/cb/Volume/2007/1/Bone-buildingscaffold.asp
Stem Cell application
A stem cell is a kind of cell produced in a four-five day old fetus, called a blastocyst, which hasn't been assigned a specific purpose in the body yet. This "unassigned" cell allows researchers to implant stem cells into dying patients to improve impaired body parts and organs. Stem cell applications, whether embryonic, adult or pluripotent, is a huge breakthrough in modern-day scientific research. For scientists, stem cells are very vital to understanding how the body works and how to improve certain body tissues and cells. As of now, the goverment is not funding adequate amounts of money to pave the way for uses for stem cells, due to ethical problems. Yet, researchers have found that stem cells can help with numerous diseases and illnesses, ranging from cancer to a "broken heart" to glaucoma.
Stem cells can be transplanted into a patient, therefore completely eliminating the problem of a non-working body organ. Stem cells can also fix chromosomal abnormalities at birth.
Stem cells can be transplanted into a patient, therefore completely eliminating the problem of a non-working body organ. Stem cells can also fix chromosomal abnormalities at birth.
Monday, July 28, 2008
interesting article about artificial joints
http://www.nytimes.com/2008/07/29/business/29hip.html?_r=1&hp&oref=slogin
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