By Nancy Lapid
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An experimental hormone-free birth control pill for men appears to be safe based on early human trials and successfully prevented sperm production in mammal studies, according to the company developing it.
In an early-stage study, the contraceptive pill was well-tolerated at a variety of doses, with no safety concerns and no serious adverse events, YourChoice Therapeutics CEO Akash Bakshi said.
A 28-day trial in 50 men aged 28-70 is now underway, and a 90-day mid-stage study is expected to start in the second quarter of this year, Bakshi said.
The drug, YCT-529, under development by YourChoice and Quotient Sciences, works by interfering with vitamin A signaling necessary for sperm production. Fertility returns when treatment is discontinued.
In mice and in primates, the pill caused infertility within two weeks, and the animals regained fertility after stopping treatment, without adverse effects, researchers reported on Thursday in Communications Medicine.
A reversible male contraceptive that is administered orally “would be the best case scenario for ease of use and compliance,” the researchers wrote.
Prostate cancer surgery follow-up may happen too soon
Doctors may be misdiagnosing some cases of prostate cancer recurrence because they are checking for it sooner than may be optimal, a new study suggests
Blood levels of prostate specific antigen that remain high after surgery for prostate cancer are indicative of residual cancer and linked to worse outcomes. The current standard is to check the PSA level at one-and-a-half to two months following surgery, but that may be too soon, researchers say.
Rather, PSA levels should be measured for three months or more to avoid overtreatment, they said on Thursday in a report published in JAMA Oncology.
During a median follow-up of more than six years among 43,000 patients who underwent surgery for prostate cancer and still had elevated PSA levels afterward, those whose level was above 20 before surgery had significantly lower rates of death from prostate cancer or from any cause compared to patients with lower PSA levels before surgery.
The researchers theorize that a higher proportion of patients with higher pre-operative PSA levels could have reached an undetectable PSA level if more time had been allowed prior to follow-up diagnoses and treatment.
“It can take longer than three months for many patients… to completely clear the PSA from their bloodstream,” study leader Dr. Anthony D’Amico of Brigham and Women’s Hospital in Boston said in a statement. Checking levels too soon can lead clinicians to mislabel a patient as having recurred and prompt them to start additional treatments, he cautioned.
Malfunctioning protein linked to Parkinson’s disease
New details about a key protein linked to early-onset Parkinson’s disease, reported on Thursday in Science, answer many long-standing questions and should aid in development of new treatments, researchers say.
Scientists already knew that in healthy people, the protein called PINK1 senses damage to mitochondria, the energy factories inside of cells. It attaches itself to the damaged mitochondria and tags them so that they can be purged.
When mitochondria are damaged, they stop making energy and release toxins into the cell. In a person with Parkinson’s and a PINK1 mutation, damaged mitochondria accumulate in brain cells and the toxins eventually kill the cells.
Researchers also knew that PINK1 mutations cause Parkinson’s disease in young adults in particular.
But until now, no one had described the protein’s structure, or how it works.
“This is the first time we’ve seen human PINK1 docked to the surface of damaged mitochondria and it has uncovered a remarkable array of proteins that act as the docking site,” study coauthor Dr. Sylvie Callegari of the Walter and Eliza Hall Institute at the University of Melbourne, Australia said in a statement
“We also saw, for the first time, how mutations present in people with Parkinson’s disease affect human PINK1,” she added.
Seeing what the protein looks like, how it attaches to the mitochondria, and how it is activated “reveals many new ways to change PINK1, essentially switching it on, which will be life-changing for people with Parkinson’s,” study leader David Komander, from the same institute, said in a statement.
(Reporting by Nancy Lapid; editing by Bill Berkrot)
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