Delaying
childbirth lowers breast cancer risk
Delaying childbirth by 15 years
after menarche may lower the odds of an aggressive form of breast cancer by
60%, says a new study.
"We found that the interval
between menarche and age at first live birth is inversely associated with the
risk of triple-negative breast cancer," said Christopher I. Li, member of
Public Health Sciences Division at Fred Hutchinson Cancer Research Centre, who
led the study.
The study involved more than
1,960 Seattle-area women between the ages of 20 and 44, 1,021 with a history of
breast cancer and 941 without, the journal Breast Cancer Research and Treatment
reports.
While relatively uncommon,
triple-negative breast cancer is a particularly aggressive subtype of the
disease that does not depend on hormones such as estrogen to grow and spread.
This type of cancer, which
accounts for only 10% to 20% of all breast cancers, does not respond to
hormone-blocking drugs such as Tamoxifen, according to a Fred Hutchinson
statement.
The study by Li and colleagues
is the first to look at how the interval between first menstrual period and age
at first birth is related to the risk of this particular type of breast cancer.
The study also confirmed several
previous studies that have suggested that breast-feeding confers a protective
effect against triple-negative disease.
"Breast-feeding is emerging
as a potentially strong protective factor against one of the most aggressive
forms of breast cancer," Li said.
Source: www.dnaindia.com
21.12.2012
New
red blood cell genes 'may help research on anaemia and malaria'
Research on conditions like anaemia and malaria
is set to get a boost following the identification of a clutch of new genes
that influence red blood cells. The discovery comes from an analysis of genetic
samples from around 135,000 people, which was carried out by a large
international team of researchers.
“This helps us understand the biological
mechanisms of what determines formation and function of red blood cells,” ABC
News quoted Dr Manuel Ferreira from the Queensland Institute of Medical
Research in Brisbane as saying.
Red blood cells are important because they
contain haemoglobin, which carries oxygen
According to Ferreira, understanding the genes
that impact the formation and function of red blood cells not only helps in
basic understanding of biology, it will also help in research on diseases such
as anaemia To investigate the genetic factors influencing red blood cells,
Ferreira and colleagues combined the results of a number of genome-wide
association studies.
These studies looked at 2.6 million genetic
variants to find out which ones show an association with 6 different red blood
cell characteristics, including red blood cell count and haemoglobin
concentration. “There were 75 positions on the genome that were strongly
associated with one or more of the red blood cell characteristics,” Ferreira
said.
He says of the genetic variants identified, 43
had not been previously identified.
Interestingly, says Ferreira, some of the
implicated genes are known to be involved in a number of rare blood diseases. He
says this shows variation in the same gene can lead to either slight
differences in red blood cell count or haemoglobin concentration, or much more
drastic conditions.
Fellow co-author Professor Peter Visscher of the
University of Queensland says the team also carried out an RNA-silencing
experiment in drosophila and compared the results with those from published
mouse studies.
These animal models confirmed the influence of a
number of the genes on red blood cells.
“It’s interesting because it shows those genes
were already important so many hundreds of millions of years ago when a common
ancestor of drosophila and humans lived,” Visscher said.
The study has been recently published in the
journal Nature.
Source: www.dnaindia.com
21.12.2012
The
quality of expectations determines the quality of our action
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