Talk about early intervention. One day, a fetus with a genetic disease may be able to get treatment before it even leaves the womb–and that treatment will come in the form of an extra gift from mom. While this scenario will only come to pass if new mouse research can be translated to humans, the finding are exciting.
The new work solves a medical mystery. When researchers realized they could diagnose a fetus with certain genetic illnesses as early as the first trimester, they plunged into the search for in utero treatments. Ailments like sickle cell anemia and some immune disorders might be treatable with blood stem cells taken from a donor’s bone marrow, researchers thought: the transplanted cells would multiply and populate the fetus’s bone marrow with healthy blood-forming cells, and the fetus’s immature immune system wouldn’t reject the foreign entities. But when researchers tried such transplants, they didn’t work.
“The fact that fetal stem cell transplantation has not been very successful has been puzzling, especially given the widely accepted dogma that the immature fetal immune system can adapt to tolerate foreign substances,” said co-senior author Qizhi Tang…. “The surprising finding in our study is that the mother’s immune system is to blame.” [press release]
Perhaps you’ve seen the story of the 44-year-old American man reportedly “cured” of HIV in Germany–it’s been making the rounds over the past week. What’s actually happening here?
This is a story that dates back a few years; in fact, 80beats blogged about this case years ago when it first made the news. Back in 2007, the man—Timothy Ray Brown—was an HIV-positive patient suffering from acute myeloid leukemia. When standard chemotherapy couldn’t help him, his docs in Germany turned to a bone marrow transplant, with one twist.
Brown’s oncologist decided to look for a bone marrow donor who had a had a special genetic mutation that made the stem cells in it naturally resistant to HIV infection. His physician, Dr. Gero Huetter, was able to find this rare match and Brown got the bone marrow transplant. He needed a second stem cell transplant because the cancer came back. Today, he appears to be cancer free and doctors can’t find traces of the virus that causes AIDS either. [CNN]
Brown’s treatment made a splash in the news in 2008, when the doctors first reported on it. It has resurfaced this month because the researchers published a new study in the journal Blood updating his condition.
The researchers confirmed that Brown seems to have maintained his resistance to HIV for three years, confounding their expectation that he would become reinfected. They concluded that a “cure of HIV has been achieved in this patient.” [New Scientist]
Researchers have built miniature human livers in the lab, which could lead to better drug discovery and could even point the way toward implantable artificial organs. The mini-livers seem to act like human livers in the lab, but it remains to be seen how well they’ll survive and perform when transplanted into animals or, maybe one day, humans.
“We are excited about the possibilities this research represents, but must stress that we’re at an early stage and many technical hurdles must be overcome before it could benefit patients,” said Shay Soker, Ph.D., professor of regenerative medicine and project director. “Not only must we learn how to grow billions of liver cells at one time in order to engineer livers large enough for patients, but we must determine whether these organs are safe to use in patients.” [Press release].
The researchers at Wake Forest’s Institute for Regenerative Medicine created livers that weigh about 0.2 ounces each. That’s not nearly large enough to keep a human alive (it would need to be about 80 times larger for that), but getting the organ made was a feat in itself. The livers were made using the extracellular scaffolding from an animal liver, after all of the animal’s cells had been gently removed from it.
Researchers have designed the first artificial kidney small enough to slip comfortably inside the human body, and they say the technological breakthrough could be an enormous benefit for people grappling with kidney disease. Modern medicine can keep patients alive if their kidneys fail via external dialysis machines that filter toxins from their blood, but it’s a grueling and imperfect process.
Patients must be tethered to machines at least three times a week for three to five hours at a stretch. Even then, a dialysis machine is only about 13 percent as effective as a functional kidney, and the five-year survival rate of patients on dialysis is just 33 to 35 percent. To restore health, patients need a kidney transplant, and there just aren’t enough donor organs to go around. In August, there were 85,000 patients on the U.S. waiting list for a kidney … while only 17,000 kidney transplants took place last year. [Technology Review]
Six patients’ eyes have connected with “biosynthetic” replacement corneas, growing nerves and cells into the fakes as if they were real human tissue. With more trials and improvements in implant technique, researchers say the biosynthetic corneas might replace the expensive, rejection-prone, and scarce cadaver corneas that are currently used in transplants. This is good news for people who have lost vision due to inflamed or scarred corneas, and who are hoping to bring the world back into focus.
The findings appeared yesterday in Science Translational Medicine. The corneas allowed six out of a total of ten trial patients with advanced keratoconus, a condition which causes corneal scarring, to see just as well as if they had a traditional cadaver cornea replacement. Natural corneas, which refract light coming into the eye and help it to focus, consist of parallel strands of collagen; the biosynthetic corneas used collagen made in a lab by the biotech company Fibrogen.
“This study … is the first to show that an artificially fabricated cornea can integrate with the human eye and stimulate regeneration,” said May Griffith of the Ottawa Hospital Research Institute, who led the study. “With further research, this approach could help restore sight to millions of people who are waiting for a donated human cornea for transplantation.” [Reuters]
Obsessive-compulsive mice, which were once pulling their hair out from too much grooming, are now sitting pretty. Their cure? A bone marrow transplant. In a study published today in Cell, scientists show an unsuspected link between a psychological disorder and the immune system.
Here’s how they did it:
Step 1 – Finding the Problem
Since excessive cleaning is a behavior, scientists first thought to look for defects in the mouse brain. They noticed that mice with a mutant version of the gene Hoxb8 were the ones cleaning themselves bald. Hoxb8 is important for creating microglia–nervous system repair cells that search for damage in the brain.
Although some microglia start out in the brain, others are born in the bone marrow and move in. Overall, adult mice with faulty Hoxb8 harbored about 15% fewer microglia in the brain than normal. [ScienceNow]
Since many microglia move from bone marrow to brain, the scientists decided to give the compulsive mice, with the mutant Hoxb8 gene, a marrow transplant.
A hospital in Barcelona has announced that it has successfully carried out the world’s first full face transplant.
A team of 30 doctors conducted a 24-hour surgery on the patient who had lost most of his face in an accident; in the end the surgeons gave him new jaws, cheekbones, nose, teeth, skin, and other features.
The patient now has a completely new face from his hairline down and only one visible scar, which looks like a wrinkle running across his neck, said Dr. Joan Pere Barret, the surgeon who led the team [Associated Press]. She added that if you ran into the patient at the hospital now, you would not notice anything unusual.
This is the first time that doctors have performed a total facial transplant. Over the past few years, partial facial reconstructions have been performed on ten patients, including on an American woman who suffered an unspecified trauma and a Chinese farmer whose face was mauled by a bear. All the patients were put on a strict regime of immunosuppressant drugs after surgery to ensure that their bodies didn’t reject the transplanted bones, muscles, and skin, and were also given psychiatric counseling.
The current Spanish patient is reportedly a farmer in his 30s who accidentally shot himself in the face in 2005. Prior to the face transplant, he had to breathe and be fed through tubes. After looking at himself in the mirror, post-surgery, he is said to be happy with his new visage.
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Image: Valle d’hebron Hospital
Linda De Croock, a Belgian woman who had her throat crushed in a car accident a quarter-century ago, received one of the odder-sounding organ transplants we’ve ever heard: For two years, De Croock had a dead man’s windpipe growing inside her arm. Reporting in the New England Journal of Medicine, her doctors say they successfully implanted the donated trachea in her forearm and then moved it from there to where it belongs.
While the arm might seem a questionable place to put a windpipe, the point was to acclimate her body to the new organ and get her off anti-rejection drugs. Doctors at Belgium’s University Hospital Leuven implanted the donor windpipe in De Croock’s arm as a first step in getting her body to accept the organ and to restart its blood supply. About 10 months later, when enough tissue had grown around it to let her stop taking the drugs, the windpipe was transferred to its proper place [Canadian Press]. Since De Croock’s own tissue has grown around the windpipe, her body no longer considers it foreign and dangerous. A year has passed since the surgery to move the windpipe from her arm to her throat, and the doctors report she is doing well.
Emphysema and cystic fibrosis patients who need new lungs are faced with a life-threatening problem: more than 80 percent of donated lungs can’t be used—they’re inflamed and barely functional [Scientific American]. Transplanted lungs also fail at a much higher rate than other transplanted organs, as they’re more likely to be rejected by the recipient’s body. But a new procedure that makes use of gene therapy may soon double or triple the supply of undamaged donated lungs, and may also improve their function once transplanted.
In both pre- and post-transplant lungs, the problem is inflammation caused by insufficient amounts of an immune molecule called IL-10. Donated lungs are immediately chilled on ice, which destroys any IL-10 that may remain in the lungs, allowing substantial damage to occur before the organ can be implanted. And a lack of the molecule after transplantation increases the likelihood that inflammation will damage the organ and induce rejection [Los Angeles Times].
To get around these problems, the researchers first built a domed chamber where pig lungs were kept at body temperature with a steady flow of oxygen and nutrients moving through them. That arrangement alone prevented substantial damage to the lungs. Next, in the gene therapy stage, the researchers used a harmless virus to bring a gene that produces IL-10 into the lung cells.
British doctors claim to have made an important step toward completing the first womb transplant. They say they have solved the problem of keeping the blood flowing to the transplanted uterus so that a pregnancy can be carried to term in the recipient. Womb transplants, if proven successful in humans, would offer an alternative to surrogacy or adoption for women whose own wombs have been damaged by diseases such as cervical cancer. Around 15,000 women of childbearing age are currently living with a womb that does not work or were born without one [Guardian]. The research was presented at the American Society for Reproductive Medicine (ASRM) conference in Atlanta.
However, the technique has only been demonstrated in rabbits, a far cry from successfully completing a womb transplant in humans. Using a “vascular patch technique” major blood vessels including the aorta were connected. Two of the five rabbits lived to 10 months and dissection after death showed the womb had stayed healthy [BBC News]. The research team has yet to show that the new wombs can actually support a pregnancy, which leaves some scientists skeptical that the procedure is actually an advancement.
Ethicists, medics and feminists have long argued as to whether infertility is a disease or a cultural phenomenon born of a society where women feel they have no value if they cannot reproduce. But illness or otherwise, it is not a fatal disease, and the suggestion that women could undergo major transplant surgery to fulfill their desire for a child may prompt unease [BBC News]. A woman who received the transplant would have to take drugs to suppress her immune system to prevent her body from rejecting the foreign organ. To avoid taking the drugs for life, the uterus would likely be removed again after the desired babies had been born.
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