How To Lose Weight?
Friday, February 1, 2013
Wednesday, January 30, 2013
Saturday, January 26, 2013
Torsión de estómago y esplenectomía en un Chow-chow. Cirugía Miraflores del Palo
En este caso mostramos la resolución quirúrgica de una torsión gástrica en una perra Chow-Chow de 6 años. Por la naturaleza de la torsión fue imposible introducir la sonda orogástrica, lo que nos obligó a introducirla durante la cirugía. El bazo ofrecía dudas en cuanto a la viabilidad de su vascularización y presentaba un nódulo de pequeño tamaño, por ello decidimos sacarlo. El animal se recuperó satisfactoriamente.
Thursday, November 1, 2012
Revolution in Neurology Brain Implant Brings Paralyzed Muscles Back to Life
— An artificial connection between the brain and muscles can restore complex hand movements in monkeys following paralysis, according to a study funded by the National Institutes of Health.
In a report in the journal Nature,researchers describe how they combined two pieces of technology to create a neuroprosthesis — a device that replaces lost or impaired nervous system function. One piece is a multi-electrode array implanted directly into the brain which serves as a brain-computer interface (BCI). The array allows researchers to detect the activity of about 100 brain cells and decipher the signals that generate arm and hand movements. The second piece is a functional electrical stimulation (FES) device that delivers electrical current to the paralyzed muscles, causing them to contract. The brain array activates the FES device directly, bypassing the spinal cord to allow intentional, brain-controlled muscle contractions and restore movement.
The research team was led by Lee E. Miller, Ph.D., professor of physiology at Northwestern University’s Feinberg School of Medicine in Chicago. Prior to testing the neuroprosthesis, Dr. Miller’s group recorded the brain and muscle activity of two healthy monkeys as the animals performed a task requiring them to reach out, grasp a ball, and release it. The researchers then used the data from the brain-controlled FES device to determine the patterns of muscle activity predicted by the brain activity.
To test the device, the researchers gave monkeys an anesthetic to locally block nerve activity at the elbow, causing temporary paralysis of the hand. With the aid of the neuroprosthesis, both monkeys regained movement in the paralyzed hand, could pick up and move the ball in a nearly routine manner and complete the task as before.
Dr. Miller’s research team also performed grip strength tests, and found that their system restored precision grasping ability. The device allowed voluntary and intentional adjustments in force and grip strength, which are keys to performing everyday tasks naturally and successfully.
This new research moves beyond earlier work from Dr. Miller’s group showing that a similar neuroprosthesis restores monkeys’ ability to flex or extend the wrist despite paralysis. “With these neural engineering methods, we can take some of the important basic physiology that we know about the brain, and use it to connect the brain directly to muscles,” Dr. Miller said. “This connection from brain to muscles might someday be used to help patients paralyzed due to spinal cord injury perform activities of daily living and achieve greater independence.”
In 2008, a team led by Eberhard Fetz, Ph.D. at the University of Washington in Seattle coupled the activity of single neurons to an FES device similar to the one used for Miller’s study. Monkeys learned to activate individual neurons to control the FES device and move a joystick, and could adapt neurons previously unassociated with wrist movement to complete the task. The investigators suggest that this process of learning and adaption plays an important role in how the BCI translates the brain’s activity patterns into adaptive control of the FES device.
The unique design of the ball grasp-and-release task used with the animals in this study is a further contribution to advanced neuroprosthetic testing and development. Daofen Chen, Ph.D., a program director at NIH’s National Institute of Neurological Disorders and Stroke (NINDS), described how researchers in the field are striving toward devices that will go beyond simple arm movements and allow fine hand and finger movements. “We’ve learned a lot from non-human primate studies focused on
understanding neural control of arm and wrist movements,” said Dr. Chen. “Dr. Miller’s study builds on those efforts and focuses on the complex hand and finger movements needed to grasp an object.”
FES devices are currently used for foot drop, a clinical condition seen in patients with stroke or partial spinal cord injury where weak or paralyzed muscles cause the toes to catch on the ground while walking, leading to trips and falls. FES can be activated with shoe sensors, or coordinated with walking movements, to stimulate muscles and lift the toes at the appropriate time during a step.
Other FES devices in current clinical use take advantage of the patient’s residual muscle activity. For example, a prosthetic arm can use sensors built into the shoulder, sensing a shrugging motion that is used to stimulate muscles to open or close the hand. However, this is a less precise and less natural method of control, and it is not an option for patients with higher level spinal cord injuries and little or no shoulder and arm movement. For these patients, the creation of a brain-controlled FES device that connects brain activity directly to muscle stimulation would provide an opportunity to restore hand function.
The temporary nerve block used in the current study is a useful model of paralysis, but it does not replicate the chronic changes that occur after prolonged brain and spinal cord injuries, Dr. Miller cautioned. He said the next steps include testing this system in primate models of long-term paralysis, and studying how the brain changes as it continues to use this neuroprosthesis.
The paper was coauthored by researchers Christian Ethier, Ph.D. and Emily Oby at Northwestern University, Chicago and Matt Bauman, now at the University of Pittsburgh. The research was supported by the National Institutes of Health/NINDS (grant #NS053603), the Chicago Community Trust through the Searle Program for Neurological Restoration at the Rehabilitation Institute of Chicago, and the Health Research Fund of Quebec, Canada.
Monday, October 22, 2012
أفراد من الشرطة يطلقون دفعات من الرصاص ويحاصرون مستشفى المحلة العام
فى تمام الساعة الثامنة صباحا قام بعض افراد من الشرطة
باطلاق اعيرة نارية كثيفة فى الهواء داخل
مستشفى المحلة العام مما تسبب فى حالة من الهلع والرعب داخل المستشفى كما قاموا
باغلاق جميع مداخل ومخارج المستشفى من الساعة الثامنة صباحا ولمدة 3 ساعات ومنعوا
الاطباء والتمريض والمرضى من الدخول او الخروج وذلك احتجاجا على وفاة زميل لهم
يدعى/حسن فوزى حسن الذى قتل امس باعيرة نارية وعدم حضور الطبيب الشرعى . علما بان
الطبيب الشرعى لايعمل بالمستشفى ويستدعى عند اللزوم لمناظرة الحالات وقد ترتب على
ذلك توقف العمل بالمستشفى وفور فك الحصار عن المستشفى قام العديد من الاطباء والتمريض بمغادرة
المستشفى فورا فى حالة من الهلع والرعب
Tuesday, October 2, 2012
Heart Transplantation Complete Video
On September 19th, 2007 The Department of Cardiothoracic Surgery at the Montefiore-Einstein Heart Center in New York presented an OR-Live.com webcast of a panel discussion on a heart transplant. This procedure was performed on April 17, 2007 by Dr. David D'Alessandro, Cardiothoracic Surgeon at the Center. Dr. Ricardo Bello was the assisting surgeon during the procedure. The panel discussion was moderated by Dr. Daniel Goldstein, Surgical Director of Cardiac Transplantation, Montefiore-Einstein Heart Center. They were joined by a live audience of surgeon-colleagues and cardiologists. The webcast featured video portions of the procedure as well as detailed descriptions of the techniques used.
Friday, August 10, 2012
How Can Human Stem Cells Help to Restore Memory?
StemCells Inc. hopes a clinical trial of its proprietary stem cells in rodents will lead to a clinical trial with Alzheimer's patients.
Last week, a California biotech company announced that its human stem cells restored memory in rodents bred to have an Alzheimer's-like condition—the first evidence that human neural stem cells can improve memory.
The company, called StemCells, is betting that its proprietary preparation of stem cells from fetal brain tissue will take on many different roles in the central nervous system. The company and its collaborators have already shown that its stem-cell product has potential in protecting vision in diseased eyes, acting as brain support cells, or improving walking ability in rodents with spinal cord injury.
This metamorphic ability is not so surprising—they are stem cells, after all. But experts say the quality of scientists involved in StemCells and the interesting properties of its cells sets the company apart. "They've really been steadfast in their work to get these cells into clinical trials. That is a tough road and they've done it," says Larry Goldstein, a neuronal stem-cell researcher and director of UC San Diego's stem-cell program.
and has since spent some $200 million improving the technology. "Now we are really in the exciting phase, because now we are looking at human clinical data, as opposed to just small animals," says StemCells CEO Martin McGlynn.
His company is not the only group bringing stem cells into the clinic. While much attention was paid to Geron's departure from the world's first embryonic stem cell trial (see "Geron Shuts Down Pioneering Stem-Cell Program"), many other groups have continued to push their non-embryonic stem-cell therapies forward for leukemia, colitis, stroke, and more. Meanwhile, Advanced Cell Technologycontinues its U.K.-based embryonic stem-cell therapy trials for blindness. Non-embryonic stem cells can come from a variety of sources—bone marrow, blood, as well as donated aborted fetal tissue, as is the case with StemCells and Neuralstem, another company focused on neuronal stem cells. In recent years, scientists have also developed methods for turning normal adult cells into stem cells (so-called induced pluripotent stem cells), but their safety has yet to be tested in humans.
So while StemCells is not a lone wolf, it may well be a pack leader. One of StemCells' first human studies involved a small trial of young children with a rare and fatal neurodegenerative disease called Batten disease. In 2006, the company began the first U.S. Food and Drug Administration-authorized trial of human neural stem cells at Oregon Health and Science University. Through small boreholes in the skull, a neurosurgeon implanted as many as a billion neural stem cells into different locations of the brains of six Batten patients.
The trial has since suggested that the cells are safe and integrate into the brain. At first, the children received immune system-suppressing drugs to prevent their body from rejecting the cells. But after a year, that treatment was stopped. "A big question that we had, that science had, that the FDA had, was what happens to these cells when you withdraw immunosuppression?" says McGlynn.
The treatment, however, did not rescue the children from the effects of the disease, and some have since succumbed to the disorder. Some of the parents of the children who passed away gave permission for an autopsy, enabling the scientists to see that even after one and a half years with no immunosuppression, the transplanted cells had survived. The company wanted to try the cellular therapy in children at an earlier stage of the disease, but was unable to find eligible patients at such a point in the disease course and canceled the trial.
In another small trial, the cells have shown the ability to make functional changes in the human brain. At the University of California, San Francisco, four children with a genetic disease that prevents their brains from producing myelin—the insulating sheath on neurons that is necessary for proper electrical signaling—received the cellular treatment. In StemCells' study, three of the treated boys had small but measureable gains in neurological function, while the fourth remained stable. MRI scans indicate that the boys' neurons have gained more myelin sheaths, which remain even after immunosuppression is removed.
The company has also initiated trials in patients with spinal-cord injuries and macular degeneration, a disease of the eye that gradually destroys central vision. Its Swiss-based trial with spinal-cord injury patients, begun in 2011 at the University of Zurich, has so far enrolled three patients, two of which have reported changes in their sensitivity to touch. These patients each received a direct transplant of 20 million stem cells into the spinal cord. Last month, the company also announced the beginning of a trial for dry age-related macular degeneration, for
which there are currently no FDA-approved treatments. A trial at the Retina Foundation of the Southwest in Dallas will test stem cells in the eyes of up to 16 patients.
But even with years of solid lab animal data and promising first starts in humans, success is no guarantee. "Animals only tell you a subset," says Goldstein. "Who knows what's going to work for which disease. When you get to clinical trials for people, all bets are off."
Friday, July 6, 2012
Medical Benefits Of Nanotechnology
Overview: Molecular manufacturing (MM) will impact the practice of medicine in many ways. Medicine is highly complex, so it will take some time for the full benefits to be achieved, but many benefits will occur almost immediately. The tools of medicine will become cheaper and more powerful. Research and diagnosis will be far more efficient, allowing rapid response to new diseases, including engineered diseases. Small, cheap, numerous sensors, computers, and other implantable devices may allow continuous health monitoring and semi-automated treatment. Several new kinds of treatment will become possible. As the practice of medicine becomes cheaper and less uncertain, it can become available to more people.
Surgical and diagnostic tools will be elegant and cheap. | Medicine, especially medical research, demands cutting-edge, high-tech tools. These are naturally expensive to manufacture, especially if they must be kept sterile. With a molecular manufacturing system, the cost of production is unrelated to the complexity of the product. Design and testing will still be costly, but once designed, tools can be manufactured in quantity. The incredibly small component size will allow new kinds of tools: for example, a complete surgical robot can be built smaller than a hypodermic needle, and a chemical sensor can be small enough to fit inside a living cell. Because the human body is so complex, accurate knowledge of its state requires gathering large amounts of data. The small size and low cost of nano-built sensors will allow hundreds or thousands of them to be used for routine diagnosis, whereas today only a few data points can be gathered. Integrated sampling and analysis tools will allow real-time monitoring; there will be no need for a separate "lab" to run the tests. |
Research and diagnosis will become more efficient. | Medical research has traditionally been a process of trial and error. Make a change, then wait a few hours or days to see its effect on the overall state of health. This required an extremely conservative approach, as medical techniques had to evolve one step at a time. With real-time monitoring of the body's systems, it will be possible to detect undesired effects far earlier, allowing a more aggressive and experimental approach to treatment. Researchers will be able to gather far more data and process it with computers millions of times more powerful. The result will be a detailed model of the body's systems and processes, and the ability to predict the effects of any disease or treatment. Diagnosis will also be far easier and more informative. It will be possible to build thousands of diagnostic tests, including invasive tests and imaging tests, into a single, cheap, hand-held device. A variety of single-molecule detection technologies will be available even with early MM. Trustworthy diagnosis will make medicine far more efficient, and also reduce the risk of malpractice (and thus liability insurance). |
Small medical devices can be implanted permanently. | Today, only a few medical devices are implanted permanently. Surgery is always undesirable, and not much functionality can be packed into a device small enough to wear inside the body. Nano-built devices will be far more efficient and compact. As MM technologies gain the ability to synthesize chemicals other than diamond, implantable devices will be able to continuously sense and adjust the body's chemical balance, in the bloodstream or in specific tissues. Even before then, implanted sensors will be valuable in acquiring a continuous record of the person's state of health. This will allow more sensitive adjustment of the body's state, and earlier detection of problems. |
More medical problems will be prevented. | Many medical problems are preventable. Some are acquired from the environment, including poisoning, some cancers, and almost all infectious disease. Widespread monitoring of health and the environment will allow detection of the source of such problems before they can injure people. Improved infrastructure such as water filtration will also help to reduce environmentally-acquired disease. Other diseases are related to lifestyle. Current lifestyle advice is difficult to follow and is not always accurate. Better research will greatly improve our understanding of cause and effect, allowing us to live more healthy lifestyles with far less effort. Finally, some problems accumulate over time, and early detection and treatment can correct the problem before it turns into a full-blown disease. |
New diseases will be stopped quickly. | New diseases continue to be a threat to the human race. Naturally occurring diseases could be far worse than SARS, and an engineered disease could conceivably wipe out most of the human race. It will be increasingly important to have a technology base that can detect new diseases even before symptoms appear, and create a cure in a matter of days. MM will enable just such a rapid response. With complete genomes and proteomes for humans and for all known pathogens, plus cheap, highly parallel DNA and protein analysis and sufficient computer resources, it will be possible to spot any new pathogen almost immediately. (There is already a project under way to sequence the DNA of every organism in the Sargasso Sea.) Curing a new infectious disease will require some method of detecting and stopping the pathogen. Robert Freitas has described over a dozen nanotechnological ways to disable or destroy pathogens. |
Diagnosis and treatment may be semi-automated. | The practice of medicine today involves a lot of uncertainty. Doctors must guess what condition a patient has, and further guess how best to treat it without upsetting the rest of the body's systems. By contrast, when pathogens and chemical imbalances can be directly detected, many conditions will be treatable with no uncertainty, allowing the use of computer-selected treatment in common cases. This may further reduce the cost of medical care, although doctors, regulatory agencies, or the patients themselves may resist the practice initially. |
Health will improve and lifespans increase. | Health improvement and life extension do not depend directly on molecular manufacturing, but it will certainly make them accessible to more people. Any treatment that can be automated can be applied to any number of people at low cost. Efficient research will speed the development of cures for complex problems such as cancer and aging. New therapeutic techniques will allow the treatment of more types of diseases. |
MM will facilitate genetic therapy. | Genetic therapy holds great promise for treating several serious health problems. However, the current state of the art can also cause problems, including cancer. Eventually, we may hope that MM will be able to directly edit the DNA of living cells in the body. But even without that level of sophistication, massively parallel scanning may enable the sorting of cells modified outside the body. The ability to inject only non-cancerous cells would make some kinds of genetic therapy much safer. Microsurgical techniques could allow the implantation of modified cells directly into the target tissues. |
Some organs will be replaceable. | Many organs in the body perform fairly simple functions. Already, sophisticated machinery can replace lung function for hours, heart function for months, and kidney function for years. Since MM can build machines smaller than cells, many other organs will be candidates for replacement or augmentation, including skin, muscles, various digestive organs, and some sensory functions. |
Systems can be individually improved. | The body is made of a large number of interacting systems. The blood circulates chemicals all through the body, making each system interdependent with the others. Small, implanted devices will allow the systems to be decoupled and controlled independently to some degree. For example, it may be desirable for the brain to receive more, or less, adrenaline than the muscles. This capability of "heterostasis" may be useful in cases of trauma and disease, or for long-term health maintenance. |
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