Health Rounds: Older eggs may be made suitable for IVF
19/09/2024 22:00
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By Nancy Lapid
Sept 19 (Reuters) - Hello Health Rounds Readers! Today
we feature two early studies that might turn out to be laying
the groundwork for some paradigm-changing advances. One study
suggests it might someday be possible to "rejuvenate" eggs from
older women in order to make them suitable for assisted
reproduction therapies. The other suggests there may someday be
a way to prevent serious cases of jaundice in newborns. We also
highlight a study with encouraging data for patients with
advanced neuroendocrine tumors.
Older eggs may be made suitable for IVF
As women age, the quality of their eggs decreases and they
become less useful for in vitro fertilization. But it may
someday be possible to "rejuvenate" older eggs to improve the
likelihood of successful pregnancies and healthy babies, a study
in mice suggests.
In the ovaries, immature eggs are housed in fluid-filled
sacs called follicles. When an egg matures, the follicle
ruptures and releases the egg during ovulation.
It seems, Haiyang Wang and colleagues at the National
University of Singapore reported in Nature Aging, that moving
"aged" eggs into "younger" follicles can partially restore their
reproductive function, and in turn, generate eggs that are of
better quality for in vitro fertilization.
In experiments in mice, the researchers extracted healthy
follicles from young animals and cultured them in test tubes.
Then they extracted older eggs from their original follicles and
transplanted them into the younger follicles, whose own eggs had
been removed.
The results showed that "the quality and developmental
competence of the aged (egg) can be substantially, though not
fully, restored through 'nurturing' in a young follicular
environment," the researchers said in a statement.
There were improvements seen in the aged eggs' metabolism,
gene expression and energy production. There was also evidence
that the young follicular environment could support processes
that reduced the number of abnormal chromosomes.
In the mice, "All these improvements enhance the success of
embryonic development after in vitro fertilization, leading to a
live-birth rate around three times higher than that achieved
with aged oocytes not exposed to the young follicular
environment," the researchers said.
Of course, more research is needed to know whether these
findings can be extended to humans.
Women starting at around age 42 to 45 are typically advised
not to proceed with IVF with their own eggs because older eggs
have a higher chance of abnormalities.
Gene variant protects against jaundice in some newborns
Some babies are born with a gene variant that almost
completely protects them against jaundice, researchers have
discovered.
Many babies have jaundice in their first few days of life,
with a yellowish tinge to their skin and the whites of their
eyes. Usually, it goes away on its own. Severe cases, however,
can lead to brain damage and death. The yellow tint is caused by
bilirubin, an orange-yellow pigment formed in the liver as it
breaks down excess red blood cells.
The researchers were surprised to find that the newly
identified gene variant present in certain people affects the
babies' processing of bilirubin differently than in adults,
according to a study in Nature Communications.
They made their discovery by analyzing millions of genes in
blood samples from almost 30,000 newborn babies in Europe,
including about 2,000 with jaundice, and their parents.
The variant they found - known to be present in around 12%
of babies born in Europe and the United States - controls an
enzyme that converts bilirubin into a water-soluble form,
allowing the body to get rid of it more easily.
"We are surprised that we only see this effect in the
intestines of the babies, but not in the liver, as it is the
liver that is responsible for the metabolism of bilirubin in
adults," study leader Dr. Bo Jacobsson of the University of
Gothenburg in Sweden said in a statement.
The finding eventually may lead to development of a way to
prevent severe newborn jaundice, the researchers said.
Exelixis drug helpful in advanced form of pancreas cancer
A small percentage of pancreatic cancer cases – including
the one that affected the late Apple founder Steve Jobs - are
so-called neuroendocrine tumors. Cabometyx, from Exelixis
EXEL.O , can significantly extend the time until the disease
worsens in patients with advanced cases of these tumors,
researchers reported at the European Society of Medical Oncology
in Barcelona.
Among 95 patients with advanced pancreatic neuroendocrine
tumors in a randomized trial - all of whom had failed other
treatments - the median progression-free survival with Cabometyx
was 13.8 months, compared with 4.4 months with placebo.
Progression-free survival was also improved with Cabometyx
in 203 patients with advanced neuroendocrine tumors at other
sites in the body, although not to as great an extent. Median
progression-free survival in those patients was 8.4 months in
the Cabometyx group and 3.9 months with placebo.
"The results support the use of (Cabometyx) as a new
treatment option for patients with advanced extrapancreatic
neuroendocrine tumors or pancreatic neuroendocrine tumors whose
disease has progressed after at least one other line of therapy
... or in whom unacceptable side effects have developed after
such therapy," Dr. Jennifer Chan of the Dana-Farber Cancer
Institute in Boston and colleagues wrote in the New England
Journal of Medicine.
(Reporting by Nancy Lapid; editing by Will Dunham)
((Nancy.Lapid@thomsonreuters.com))