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Treatment in sight

Non-embryonic stem cells could treat age-related blindness

Nearly 11 million Americans suffer from age-related macular degeneration (AMD), the leading cause of vision loss in people 65 and older. Currently, no cure exists.

But now the federally run National Eye Institute has announced plans to begin human trials of a stem cell therapy to treat the disease, pending FDA approval. The treatment technique avoids the use of embryonic stem cells, which require the destruction of human embryos, and instead uses alternative lab-produced cells called induced pluripotent stem cells (iPSCs). If the human trials gain approval, it will be the first time researchers have used iPSCs to treat a human disease, said National Eye Institute researcher Kapil Bharti in a statement. And since iPSCs are made with a patient’s own cells, they face a minimal chance of rejection once implanted.

In the advanced stages of AMD, retinal pigment epithelial cells (RPEs) begin to die. Light-sensing cells in the retina, or photoreceptor cells, depend on the RPEs to supply them with nutrition and oxygen. When RPEs die, so do the retinal cells, causing blindness.

In animal studies described in the Jan. 16 issue of Science Translational Medicine, the researchers took iPSCs derived from rat and pig blood cells and programmed them to become RPEs. They then grew these cells into small, thin sheets and inserted them into the animals’ eyes between their RPEs and photoreceptor cells. The lab-made RPEs integrated with the animals’ retinas within 10 weeks and kept the remaining photoreceptor cells alive, stopping progression of the disease.

Any stem cell therapy involves the potential risk that the cells will form tumors, but when the researchers analyzed their lab-created cells, they found no mutations that would lead to tumor growth.

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Kevin Van Paassen/Sunnybrook Health Sciences Centre via AP

An Alzheimer’s patient is prepared for ultrasound treatment. (Kevin Van Paassen/Sunnybrook Health Sciences Centre via AP)

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Alzheimer’s opening?

Dementia gets the ultrasound treatment

Australian researchers say they are ready to begin testing a promising new treatment for Alzheimer’s disease. The technique, which involves guided ultrasound, could hold out hope for the 44 million people worldwide who suffer from the progressive brain disorder.

Scientists are unsure what causes Alzheimer’s, but they know it involves plaques that form when abnormal amounts of beta-amyloid protein clump together and collect between brain cells. Developing a treatment is difficult because the blood-brain barrier, which protects the brain from infections and toxins, also keeps out many drugs. Also, Alzheimer’s impairs microglial cells in the brain that usually clean up harmful proteins, and the blood-brain barrier blocks components of the immune system that could stimulate the cells back into action.

In 2015 University of Queensland scientists discovered that guided ultrasound could open spots on the blood-brain barrier of mice with Alzheimer’s. The researchers injected harmless microbubbles of air into the bloodstream of the mice, then used MRI to guide ultrasound waves to specific regions of the barrier. The sound waves caused the microbubbles to vibrate and enlarge, temporarily opening up the targeted areas. The procedure cleared almost all of the plaque from 75 percent of the mice, whose memory subsequently improved, the website IFLScience reported.

Another study, published July 25 last year in Nature, tested the safety of the method in five human patients with early to moderate Alzheimer’s. In all five patients the researchers safely opened the blood-brain barrier for less than 24 hours without the use of drugs. The procedure allowed the body’s own natural antibodies to cross the barrier and stimulate glial cells to clean out plaques. The researchers also discovered that the focused ultrasound increased the number of new brain cells in the hippocampus, a brain region involved in learning and memory.

In December the University of Queensland announced that researchers had received Australian funding to test the effectiveness of this approach and planned to begin human trials later this year.

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Pro-life in the lab

Pro-life advocates praise the Trump administration’s agency-level ban on fetal tissue research

In September, the Trump administration quietly banned scientists employed by the National Institutes of Health from acquiring new human fetal tissue for research. As effects of the ban began to reach research labs later in the year, outraged critics claimed the restraint would impede necessary medical research, such as studies to find a cure for HIV and the Zika virus. But pro-life advocates greeted the measure as a much-needed move to protect the unborn: Fetal tissue for research is usually obtained from aborted fetuses.

Congress approved the use of federal funds for fetal tissue research in 1993, during the Clinton presidency. In 2015, following the release of undercover videos that showed the sale of human fetal body parts by Planned Parenthood, the congressional Energy and Commerce Committee formed a panel to investigate human fetal tissue research.

The panel released a report in 2017 describing such research as unproductive and unnecessary for producing medical treatments. The panel’s investigators found that the overwhelming majority of current studies do not require fetal tissue, including studies of the Zika virus. The report advocated the use of other tissue types whenever possible, including adult tissue, stem cells obtained in an ethically uncontroversial manner, and fetal cells procured from the cadavers of stillborn or preborn babies who died naturally.

The NIH plans to invest $20 million toward the development of research alternatives to human fetal tissue, Science magazine reported. David Prentice, research director at the Charlotte Lozier Institute, believes this is a good first step and told me there are many ways scientists can accomplish current research goals without the use of fetal tissue.

Molecular and cell biologist Tara Sander Lee says ethical standards must always forbid the exploitation of one group of humans, such as unborn babies, for the benefit of another group. “Using the preborn as objects or means of experimentation, no matter what the outcome might prove or promise to be, constitutes an assault against their dignity as human beings created by God,” she told the Charlotte Lozier Institute.

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