How to make organ transplants last: New approaches try to train the body to welcome the replacement parts
A discussion of various strategies to prevent rejection in transplanted organs:
Because transplanted skin has a high likelihood of provoking an immune attack, researchers were skeptical that faces or extremities could be transplanted, Cameron says. But people who have gotten face and hand transplants have needed surprisingly few drugs to minimize rejection. A recipient gets a bit of a donor’s immune system, in the form of blood-producing bone marrow stem cells within the donor’s jaw, hand or arm bones.
No one knows which, if any, of these approaches will free transplant recipients to live without fear of rejection. None of the techniques has been vetted enough yet, and none has worked for everyone, Luo points out. Each patient may need a different strategy or a combination of rejection-soothing therapies. Researchers need to push ahead on all fronts and not be afraid to explore other strategies, she says: At this stage of research, “we just cannot be … fixated on one idea.”
The Cat’s Eye Nebula
The Cat’s Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Planetary nebulae have long been appreciated as a final phase in the life of a sun-like star. But only more recently have some planetaries been found to have halos like this one, likely formed of material shrugged off during earlier active episodes in the star’s evolution. While the planetary nebula phase is thought to last for around 10,000 years, astronomers estimate the outer filamentary portions of this halo to be 50,000 to 90,000 years old.
The study builds on a recent theory that the main reason that a sense of smell evolved was to aid in navigation, since most animals rely primarily on smell to find food and avoid predators. The McGill research team hypothesized that if this were indeed the case, there would be a strong link between navigation and olfaction. The researchers were able to show, for the first time, that similar regions of the brain (the hippocampus and the medial orbitofrontal cortex) are involved in these seemingly very different activities. They also discovered that the medial orbitofrontal cortex (mOFC), which is known to be involved in olfaction, is also critical to spatial memory.
What causes Alzheimer’s disease? The answer could be right under our noses, says leading expert Professor Ruth Itzhaki. Her latest paper presents a lifetime of research evidence that the herpes virus responsible for cold sores can also cause Alzheimer’s — and new data which show antiviral drugs drastically reduce risk of senile dementia in patients with severe herpes infections. The review in Frontiers in Ageing Neuroscience raises the tantalizing prospect of a simple, effective preventive treatment for one of humanity’s costliest disorders.
A multiyear clinical trial comparing medication and mental health counseling in the treatment of post-traumatic stress disorder shows that patients who chose their form of treatment — whether drugs or therapy — improved more than those who were simply prescribed one or the other regardless of the patient’s preference.