BRAIN DAMAGE Study finds brain lesions, higher markers for inflammation, and blood clotting among patients with obstructive apnea
BERLIN German researchers claimed they have found a way of blocking the formation of a toxin blamed for the onset of Alzheimer disease. The researchers from the chemistry department at Berlin's Free University said the discovery could prove useful in the development of medicines to combat the fatal brain disease. Biochemist Gerd Multhaup said his team had largely managed to inhibit the formation of amyloid-beta asse42, which destroys nerve cells and plays a key role in the onset of Alzheimer. They have patented the technique which subverts the formation of the toxin, he said. The group's findings are published in The Embo Journal science review.
STOCKHOLM Swedish researchers have successfully carried out womb transplants on four sheep, which subsequently became pregnant, a success that they say brings the prospect of human uterus transplants one step closer. The sheep were operated by laparotomy, an incision through the abdominal wall, said Prof. Mats Braennstroem of Gothenburg University. "We took the uterus outside the body, we kept it for a couple of hours outside the body," Braennstroem said. When they put the uterus back in the same body they connected it with other blood vessels and to the vagina. "After four to six weeks the sheep went back to the farm and then they have been put with rams and they have been mating and four of the five are pregnant," Braennstroem said. "I think this is successful, because what it proves is that you can put the uterus back with a different blood supply and you can do that in large animal species. I think this is one small step forward to human uterus transplantation." One of the main difficulties in the operations had been the problem of reconnecting the blood vessels, he said. Of the 14 sheep used in the research, some had not survived the operations, according to a report New Scientist. Braennstroem said that they now plan to move from removing and replacing a uterus from the same subject, to transplanting a uterus from one subject to the other. But this would bring a fresh complication-the risk of the recipient rejecting the uterus, he said.
WELLINGTON A leading New Zealand biotechnology researcher is starting trials in Russia on transplanting pig cells into diabetics, following claimed success with a test case begun in 1996. The trials will be carried out while health officials consider whether Prof. Bob Elliott should be allowed to resume his work in New Zealand, where authorities are concerned about the possible spread of pig-borne disease. Elliott is medical director of Australian-based Living Cell Technologies (LCT), which said three regimens would be tested in Russia in order to find the most appropriate, long-lasting and effective transplant possible. LCT said it had recently published evidence showing the live pig "islet cells" transplanted into a diabetes patient more than a decade ago are still producing insulin. "This has never been achieved before," Elliott said. "It is a profound step forward for safe, effective, and long-term diabetes control and shows the ability for pig cells to survive inside a human for an extended period of time and without immune suppression." The patient, Michael Helyer, now 51, is certain the treatment received in 1996 has helped him. "It's not about having fewer injections, it's about getting more control. You can't live a normal life if you're in fear of [blood-sugar] levels getting too high or low all the time," he said. In the latest issue of the scientific journal Xenotransplantation, LCT said Helyer's glycated-hemoglobin levels remained lower than the pretransplant levels, pointing to improved long-term control of blood glucose. Elliott's 1996 trials in New Zealand were blocked by health officials because of concerns that the transplant of pig cells might introduce swine diseases into the human population. LCT now wants to use breeding lines of pigs left behind in the Auckland Islands in 1852 and which have not been exposed to modern viruses. LCT chief executive Paul Tan said it is believed to be the most disease-free pig population in the world.
PARIS The first humans to receive spinal-disc transplants experienced no immune reactions and were relatively free of pain five years after surgery, Chinese doctors in Hong Kong and Beijing said. Suffering from degenerative disc herniation along the upper spine, the five patients, averaging 47 years in age, were given fresh-frozen discs from deceased donors. Five years later, all five had been relieved of neurological symptoms, and there was only mild degenerative change in the transplanted discs, the doctors who performed the operation reported in The Lancet. "With further improvements in the areas of graft preservation, repopulation of the graft with living cells, and surgical techniques," wrote lead author Dike Ruan, an orthopedic surgeon at Beijing's Navy General Hospital, replacing human spinal discs could one day become a standard procedure. "This issue is highly relevant because of the human and economic cost of spinal disease," added Wafa Skalli and Jean Dubousset in a commentary. The study shows, they agreed, that "disc transplantation could be an attractive alternative" to current treatment. The most common remedy today, a partial fusion of the disc to the spine, does not always relieve crippling pain. Full fusion works better in this regard, but often accelerates the degeneration of adjacent segments. The five operations described in the study all focused on the cervical spine, near the neck area. But "Extending this technique to the lumbar spine where the anatomy ... and magnitude of loading are more complex and hostile will be a future challenge," the doctors concluded. The spine is a complex bit of architecture that serves to protect the spinal cord, stabilize the head and trunk, and ensure mobility while being tugged at by gravity and numerous muscles.
TOKYO Japanese researchers have developed a prototype miniature robot that can be inserted through an incision and used to perform medical procedures deep inside the body. The beetle-shaped robot, which weighs five grams and measures two centimeters in length and one in diameter, is the result of three years of work by researchers from Ritsumeikan University and its partners. The tiny robot incorporates various medical devices including a small camera, sensors, and a drug-delivery injector, which could reduce the need for surgery. Data are sent to a computer through a slim cable although researchers hope to develop a transmitter. Previously miniature robots for inside the body have been designed to be swallowed and can only take pictures, although US researchers are also working on a small robot that enters though an incision to treat heart problems.
CHICAGO People who suffer from fragmented sleep due to obstructive sleep apnea are at increased risk for subtle, creeping brain damage. In a small study involving 65 men, researchers at the Showa University School of Medicine in Tokyo found that those with moderate to severe obstructive apnea had significantly more lesions on brain scans than those who had mild or no sleep disorders. The men with the greatest sleep disturbance also had significantly elevated markers for inflammation and blood clotting compared with the other men in the study. The higher rates of inflammation and blood-platelet activity, which correlated closely with oxygen deficiency, may explain why these men had more brain damage, the Japanese researchers said. People who suffer from obstructive sleep apnea wake up repeatedly during the night because of a blocked airway, preventing them from reaching the deep, refreshing stages of slumber. Some endure 100 or more arousals a night. Previous research has shown that people with the disorder are at higher risk for high blood pressure and stroke, but this study reveals the subclinical or "silent" cerebrovascular damage that may precede a major event such as a stroke. However, the investigative team also showed that treatment using a CPAP (continuous positive airway pressure) device lowered the levels of inflammation and blood clotting. Tests on 24 volunteers with moderate to severe apnea, who used a CPAP machine for three months, showed they had significantly lower levels of C-reactive protein, the marker for systemic inflammation, and two other platelet-activating proteins. A CPAP machine supplies continuous airway pressure by means of an air compressor attached to a mask. "CPAP may be an important intervention for decreasing the stroke risk in this susceptible population of obstructive-sleep-apnea patients," said Kenji Minoguchi, the lead author of the paper which appears in the American Journal of Respiratory and Critical Care Medicine.
PARIS A rare but crippling form of headache can be treated with electrodes to stimulate a nerve that causes the problem, according to two experimental studies. The implants have been successfully tested on patients with chronic cluster headaches who fail to respond to the few drugs available for this condition. Cluster headaches are excruciating events that can occur half a dozen times per day and may sometimes drive the patient to contemplate suicide. They are classified as chronic if a patient experiences these bouts 11 out of every 12 months. Previous attempts to tackle the problem through deep-brain surgery have been controversial, sometimes causing blindness or even death. In separate projects, neurologists in Britain and Belgium attached electrodes to the greater occipital nerve, which passes through the neck and at the back of the head. The implant was attached to a battery that was implanted in the chest cavity, and the patients were given an external device to control the degree of stimulation. In the British study, six of the eight patients said they were so pleased with their progress after 20 months that they would recommend the treatment to others. In the Belgian group, two patients were pain-free after a follow-up of 16 and 22 months, and three patients reported a 90-percent reduction in headache frequency. Patients found that if they switched off the external stimulator or the battery was empty, the attacks returned. But there were otherwise no side effects. The British study led by Peter Goadsby of the Institute of Neurology at University College London is published online by The Lancet. The Belgian research led by Jean Schoenen of the Headache Research Unit at Liege University, appears in The Lancet Neurology. M |
