One more U.S. Embassy employee in Havana, Cuba, has been affected by mysterious health incidents, the State Department said.
State Department spokeswoman Heather Nauert said one of two Americans recently evacuated from Cuba was “medically confirmed” to have been affected, while the other was “still being evaluated” by doctors.
25 Americans affected
In all, 25 Americans have been affected by the mystery ailment in Cuba.
“We still don’t know, to this day, what is causing it and who is responsible,” Nauert said, noting that investigations were underway in Havana as well as Guangzhou, China, where one employee experienced similar symptoms recently.
The United States has said that the Cuba incidents started in late 2016. The State Department calls them “specific attacks” but has not said what caused them or who was behind them. Cuba has adamantly denied involvement or knowledge.
Initial speculation centered on some type of sonic attack owing to strange sounds heard by those affected, but an interim FBI report in January found no evidence that sound waves could have caused the damage, The Associated Press has reported.
Warning issued in China
The State Department issued a health warning after the employee in China reported experiencing “subtle and vague, but abnormal, sensations of sound and pressure” and was diagnosed with a mild traumatic brain injury.
Secretary of State Mike Pompeo described it as a “serious medical incident.”
The new confirmation came less than a week after the U.S. renewed demands on Cuba to determine the source of the “attacks” on U.S. diplomats. Cuba responded by again denying any involvement in or knowledge of any such attacks. (VOA)
Eliminating dead-but-toxic cells occurring naturally in the brains of mice designed to mimic Alzheimer’s slowed neuron damage and memory loss associated with the disease, according to a study published Wednesday that could open a new front in the fight against dementia.The accumulation in the body of “zombie cells” that can no longer divide but still cause harm to other healthy cells, a process called senescence, is common to all mammals.
Scientists have long known that these dead-beat cells gather in regions of the brain linked to old age diseases ranging from osteoarthritis and atherosclerosis to Parkinson’s and dementia.
Prior research had also shown that the elimination of senescent cells in ageing mice extended their healthy lifespan.
But the new results, published in Nature, are the first to demonstrate a cause-and-effect link with a specific disease, Alzheimer’s, the scientists said.
But any treatments that might emerge from the research are many years down the road, they cautioned.
In experiments, a team led by Tyler Bussian of the Mayo Clinic in Rochester, Minnesota used mice genetically modified to produce the destructive, cobweb-like tangles of tau protein that form in the neurons of Alzheimer’s patients.
The mice were also programmed to allow for the elimination of “zombie” cells in the same region.
“When senescent cells were removed, we found that the diseased animals retained the ability to form memories, and eliminated signs of inflammation,” said senior author Darren Baker, also from the Mayo Clinic.
The mice likewise failed to develop Alzheimer’s signature protein “tangles”, and retained normal brain mass.
Keeping zombies at bay
A closer look revealed that the “zombies” belonged to a class of cells in the brain and spinal cord, called glia, that provide crucial support and insulation to neurons.
“Preventing the build-up of senescent glia can block the cognitive decline and neuro-degeneration normally experienced by these mice,” Jay Penney and Li-Huei Tsai, both from MIT, wrote in a comment, also in Nature.
Bussian and his team duplicated the results with pharmaceuticals, suggesting that drugs could one day slow or block the emergence of Alzheimer’s by keeping these zombie cells at bay.
“There hasn’t been a new dementia drug in 15 years, so it’s exciting to see the results of this promising study in mice,” said James Pickett, head of research at Alzheimer’s Society in London.
For Lawrence Rajendran, deputy director of the Dementia Research Institute at King’s College London, the findings “open up new vistas for both diagnosis and therapy for neurodegenerative diseases, including Alzheimer’s.”
Up to now, dementia research has been mostly focused on the diseased neurons rather than their neighboring cells.
“It is increasingly becoming clear that other brains cells play a defining role,” Rajendran added.
Several barriers remain before the breakthrough can be translated into a “safe, effective treatment in people,” Pickett and other said.
The elderly often have lots of harmless brain cells that look like the dangerous senescent cells a drug would target, so the molecule would have to be good at telling the two apart.