Research Round Up
Sunny Outlook on Rheumatoid Arthritis
|Elizabeth Arkema, MD|
A study has
found that regular exposure to sunlight-specifically ultraviolet B (UVB)-may
reduce the risk of developing rheumatoid arthritis.
Researchers looked at data from more than 135,000 nurses who participated in
Nurses Health Study (NHS) and Nurses Health Study II. UVB levels were
quantified using an assessment known as UV-B flux, which is a composite measure
of UVB radiation based on latitude, altitude and cloud cover. Exposure was
estimated based on state of residence.
There were 1,314 women who developed
rheumatoid arthritis over the study period. Among nurses in the first NHS
cohort, higher cumulative exposure to UVB was associated with a reduced risk of
developing the disease. Those with the highest levels of exposure were 21
percent less likely to develop rheumatoid arthritis than those with the least.
However, no such association for UVB exposure was found among women in NHS II,
who were younger than those in the first NHS.
"Differences in sun protective behaviors, such as greater use of sun block in
younger generations may explain the disparate results," said Elizabeth Arkema,
MD, BWH Division of Rheumatology,
Immunology and Allergy, lead study author.
Although the findings add to the growing evidence that UVB exposure is
associated with decreased risk of rheumatoid arthritis, the researchers note
that further studies need to be done to understand the mechanisms behind this.
The study was published online on February 4,
2013, in Annals of the Rheumatic
The Sound of Weight Gain
|Amir Lahav, ScD, PhD|
A research team led by Amir Lahav, ScD, PhD, BWH Department of
Newborn Medicine, has found that exposure to biological maternal sounds
while in an incubator may improve weight gain in very low-birth-weight infants
(infants weighing less than 1,500 grams [3.3 pounds]).
The researchers compared a prospective
treatment group of 16 very
low-birth-weight infants to a retrospective control group of 16 infants matched
for sex, birth-weight, gestational age, fluid and caloric intake, and scores
for neonatal acute physiology and illness severity.
Infants in the prospective treatment group
received daily exposure to recorded maternal sounds during their entire stay in
the neonatal intensive care unit. These sounds included the mother's speaking,
reading and singing voice mixed with the biological recording of her heartbeat.
Emily Zimmerman, PhD, a postdoctoral fellow
in the Lahav lab and first study author, observed that babies who were exposed
to maternal sounds had a significantly faster rate of weight gain during the
neonatal period (the first 28 days of life).
Very low-birth-weight infants receiving
biological maternal sounds gained an average of 2.16 grams per kilogram more
per day compared to their control counterparts who received routine exposure to
hospital sounds (13.13 grams/kilogram/day vs. 10.97 grams/kilogram/day,
"It is possible that the soothing effects of
the mother's voice led to an overall reduction in stress, anxiety, and restless
states, which in turn, allowed the infant to preserve more energy and improve
weight gain." said Lahav. Lahav notes that these promising results require
further evidence from larger randomized studies.
The study was published online on February 4,
2013, in the American Journal of
Insights into the Human Immune Response to the Unimaginable
|James Lederer, PhD|
A research team led by
James Lederer, PhD, BWH Department of Surgery, senior study author, developed a
mouse model that closely mirrors how the human immune system would respond if
exposed to radiation and injury from a radionuclear event.
They found that the immune
system's response to radiation plus trauma injury differs significantly from
radiation or trauma injury alone. According to the researchers, this is an
important problem to address because history shows that a radionuclear
explosion will cause both traumatic injuries and radiation exposures.
Importantly, the research
team developed this model in outbred mice rather than more commonly used inbred
mice to better represent the human response to these complex injuries. They found that mice that were exposed
to radiation plus trauma had lower injury survival, as well as lower bacterial
sepsis survival rates compared to mice with single injuries.
exposure caused dose-dependent losses of immune cells, but they found that B
and T cells were more sensitive to radiation, while macrophages, dendritic
cells and natural killer cells were more resistant. However, radiation alone
and radiation with trauma did induce unique increases in the percentages of
CD4+ regulatory T cells, as well as a subset of macrophages known as GR-1+
macrophages. Furthermore, mice exposed to radiation plus injury developed a
sustained pro-inflammatory immune system phenotype for up to 28 days after
injuries, especially in mice exposed to low radiation doses.
"Although we do not want
to believe that this type of a disaster will ever happen, we used this model
and the information gained to develop treatments that could be given after a
radionuclear event to protect people in harm's way," said Lederer. "Our ongoing
research shows that it is possible to partially restore immunity by giving mice
immune stimulants that target immune cell populations that survive these
complex injuries. Although it is
not a happy topic, we can't ignore the possibility of a nuclear event. We need
to be prepared and we hope that our research work will help."
The study was published in
the January 2013 issue of Radiation Research.