By Nancy Lapid
(Reuters) -This is an excerpt of the Health Rounds newsletter, where we present latest medical studies on Tuesdays and Thursdays. To receive the full newsletter in your inbox for free sign up here.
Researchers are a step closer to learning how congenital kidney defects develop in the fetus and how they might be prevented, a new report shows.
For the first time, they can watch miniature human fetal kidneys develop in test tubes over periods that simulate the course of a pregnancy.
So-called kidney organoids have been grown in test tubes before, but only starting with pluripotent stem cells – immature cells found in early embryos that can differentiate into any cell type in the body but without the tissue-specific characteristics that would allow them to perform an organ’s specialized functions.
In contrast, the new organoids are grown in test tubes using the same fetal progenitor stem cells that are destined to develop into human kidneys. These cells are capable of building, maintaining and repairing specific organs – in this case, the kidneys.
While kidney organoids grown from pluripotent stem cells have survived in test tubes for weeks, the new organoids built from the human fetal kidney stem cells can survive and grow for six to eight months, essentially allowing researchers to observe human kidney development as it would happen during a pregnancy, the research team reported in The EMBO Journal.
“Once we had the tissue stem cells coming from the developing human kidney in the Petri dish, they did the job because this is what they do in nature,” said Dr. Benjamin Dekel of Safra Children’s Hospital at Sheba Medical Center and Tel Aviv University, who led the research.
“The cells are self-assembling. They know how to self-organize and how to self-renew, (that is) make copies of themselves,” Dekel said.
At the same time, Dekel continued, the cells begin to differentiate, developing qualities that make them appropriate for different roles. Researchers can watch as kidney tubules, ducts, blood vessels and other renal tissues are formed.
In his clinical practice, Dekel treats children with kidney diseases.
He hopes eventually to use the organoids to study kidney malformations and to isolate genes that lead to birth defects, develop new treatments in the field of regenerative medicine and test the toxicity of drugs during pregnancy on fetal kidneys.
In the meantime, he said, it’s frustrating to watch as patients’ chronic kidney disease worsen into end-stage renal disease.
“Then we need to give them a kidney transplant or to put them on dialysis, which is really a very poor solution,” he said.
MOVING CLOSER TO EFFECTIVE VACCINES FOR HPV-RELATED CANCERS
New findings help explain why experimental treatments for cancers caused by human papillomavirus infections have been less than effective, researchers say.
The most common cancer-causing strain of HPV undermines the body’s defenses by reprogramming immune cells surrounding the tumor, earlier research has shown.
Blocking this process can boost the ability of experimental treatments for HPV to eliminate cancer cells, according to a report published in the Journal for ImmunoTherapy of Cancer.
While vaccines exist to prevent HPV infections, researchers have failed to develop effective “therapeutic vaccines” for use after HPV infections have occurred – and the new study helps explain why.
Experimental therapeutic vaccines target HPV-infected cells with immune cells known as T-cells. But in tests in mice and cell cultures, researchers found that two HPV proteins, E6 and E7, prompt nearby cells to release a protein called IL-23 that prevents the body’s T-cells from attacking the tumor.
“In order to eliminate the cancer, T-cells need to proliferate and destroy infected cells. But IL-23 stops them from working effectively, so the tumor keeps growing,” study leader W. Martin Kast of the Keck School of Medicine of the University of Southern California said in a statement.
Drugs that inhibit IL-23 are already approved for treating psoriasis and other conditions, the researchers said.
“The fact that these antibodies are already FDA-approved for something else makes this approach promising — and it also allows for rapid translation into the clinic,” Kast said.
He and his team are now developing their own therapeutic vaccine, which they will test in combination with antibodies that block IL-23.
IL-23 is also found at high levels in testicular and bladder cancers, the researchers noted, adding that further research is needed to clarify what role IL-23 plays in those diseases.
EARLY HEARING AID USE MAY HELP STAVE OFF DEMENTIA
Hearing loss is a known risk factor for dementia, but early intervention might lower that risk, a new study suggests.
Researchers performed hearing tests in nearly 3,000 volunteers without dementia who were at least 60 years old.
Over the next 20 years, the researchers saw a 61% lower risk for eventual dementia among those with newly diagnosed hearing loss who started wearing hearing aids before age 70, compared to participants diagnosed with hearing impairment at a similar age who did not get hearing aids, they reported in JAMA Neurology.
Hearing aid use did not appear to protect against dementia in people diagnosed with a hearing problem after age 70, however.
“Only 17% of individuals with moderate to severe hearing loss use hearing aids,” the researchers noted.
“Our study underscores the importance of early intervention” to reduce the risk of dementia associated with hearing loss, they concluded.
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(Reporting by Nancy Lapid; Editing by Mark Porter)
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