People who tend to raise large families won’t be pleased to hear about the
latest retrospective study published in the journal Pediatrics, which found that
the shorter the spacing between births, the higher the risk that the next child
will suffer from autism. The research by Columbia University Prof. Peter Bearman
and colleagues, who studied the records of over 500,000 California births
between 1992 and 2002, suggests that babies born less than 24 months after their
older sibling are significantly more likely to be autistic than those born at
least three years afterwards.
The New York researchers controlled for the
age of the parents and other factors and excluded children whose older sibling
was autistic. They were surprised to find the connection, but found no other
explanation than birth spacing, as they had ruled out subjects with other risks
for autism. But the researchers stressed that more studies are needed to confirm
Although the results were clear, the reasons for the
phenomenon were not. It was suggested that the baby born within two years of a
sibling’s birth might have suffered from inadequate nutrition, including lack of
the B-vitamin folic acid, which can cause birth defects. It could also be a
combination of factors.
Asked to comment, longtime Shaare Zedek Medical
Center neonatologist Prof.
Arthur Eidelman told The Jerusalem Post
the finding was a “most intriguing observation, and compatible with previous
observations that birth spacing is a factor in the health of the subsequent
pregnancy; as shortened spacing is also associated with an increased rate of
prematurity. As we do not fully understand the mechanism, I cannot say a
nutrition supplement will solve the whole [autism] problem, but preconception
supplementation of folic acid is definitely recommended.”
British doctor Andrew Wakefield published a paper in The Lancet in which he
claimed that autism was caused by measles-mumps-and rubella vaccination. Many
people believed his findings and avoided giving their children MMR vaccines,
thus leading to more cases. Almost a year ago, the journal apologized and
retracted Wakefield’s paper when it was proven that his work was deliberately
faked “junk science.” This was followed less than two weeks ago by an analysis
in the BMJ (British Medical Journal) proving Wakefield’s study was fraudulent
based on data falsification. According to experts, one out of 100 children
suffer from some kind of autism, with it more common in boys than in
girls.STRICTER RULES FOR ANIMAL EXPERIMENTATION
As two years have passed
since the global Helsinki Declaration amendment protecting animals used in
medical experimentation was not turned into an updated Israeli law, Health
Ministry director-general Dr. Ronni Gamzu decided to introduce changes through a
The previous rules going back to 1975 required all human
medical experimentation to be preceded by experiments on animals. In 2000, the
Helsinki Declaration added that animal experimentation may be carried out only
“as appropriate,” meaning that only the minimum number of animals be included to
reach conclusions regarding medications or procedures for human experimentation.
In 2008, it was further updated to say that consideration must be taken to
protect the animals’ welfare, meaning – among other things – that they should
not suffer unnecessarily.
As nothing was done to make the 2008 amendment
law in Israel, Gamzu said he would make it an “addition” to the previous law and
release the stipulations to all relevant parties. Now, in every case of animal
experimentation, only the number of animals needed to test efficacy and safety
can be used, and the animals’ welfare must be protected. Gamzu continued that in
each case, if simulations can be used instead of animal testing, animals should
not be experimented on.AMNIOCENTESIS COULD BE REPLACED BY BLOOD TEST
Hong Kong researchers have found that an experimental DNA blood test for
pregnant women can almost eliminate the need for invasive amniocentesis or a
chorionic villus sample to detect Down Syndrome in their fetuses. The need for
invasive testing can be cut by 98 percent, according to Prof. Dennis Lo and
colleagues from the Chinese University of Hong Kong, writing in the British
Medical Journal (BMJ).
The blood test uses the latest DNA technology to
analyze genetic components in the mother’s blood that indicate whether the fetus
has the syndrome.
Down syndrome, caused by an extra copy of the 21st
chromosome, occurs in around 1 in 800 births, but older women are at higher
risk. Women in high-risk groups tend to undergo a combination of scans and
hormone-level tests to determine if they need an invasive test, which involves
taking samples of genetic material from the fetus. However, the tests carry a 1%
risk of miscarriage.
The team used the most up-to-date DNA technology to
test the blood samples from 753 pregnant women – all were at high risk of having
a baby with Down’s – living in Hong Kong, the UK and the Netherlands. Eighty-six
of the women were found to be carrying a fetus with Down syndrome. The results
show that the test is highly accurate in detecting the syndrome, and does not
give false negative results.
The authors concluded that the blood test
could be used to accurately rule out Down syndrome among high-risk pregnancies
before invasive sampling is considered, thereby reducing the number of invasive
procedures.NORMAL BODY TEMPERATURE HELPS FIGHT FUNGUS
temperature – 37 degrees Celsius – is the perfect temperature to ward off fungal
infection, but not so hot that we need to eat nonstop to maintain our
metabolism, according to two researchers at Yeshiva University’s Albert Einstein
College of Medicine in New York.
“One of the mysteries about humans and
other advanced mammals has been why they are so hot compared with other
animals,” said study co-author Prof. Arturo Casadevall, a microbiologist and
immunologist at Einstein. “This study helps explain why mammalian temperatures
are all around 37° C.”
The research builds upon his earlier work showing
that the number of fungal species that can thrive and therefore infect an animal
declines by 6% for every one degree Celsius rise in temperature. This means that
tens of thousands of fungal species infect reptiles, amphibians and other
cold-blooded animals, but only a few hundred harm mammals. Such protection
against fungal infection, Casadevall has speculated, could have been crucial for
the triumph of mammals following the age of dinosaurs.
Casadevall and his
Einstein coauthor, Prof. Aviv Bergman, devised a mathematical model that
analyzed the benefits gained by body temperatures that protect against fungi
versus the costs (in terms of extra food consumption) required to maintain body
temperatures between 30° and 40° C. The optimal temperature for maximizing
benefits while minimizing costs was found to be 36.7° C, which is very close to
normal body temperature.
“This study is a good example of how mammalian
evolution has been driven by both external biological factors and internal
physiological constraints,” Bergman concluded.