Can taking the pill dull a woman's desire forever?
27 May 2005
Special Report from New Scientist Print Edition


ORAL contraceptives may free a woman to have sex without fear of
getting pregnant, but they could also extinguish her desire.

The pill has been associated with many side effects, including blood
clots, migraines and weight gain. Perhaps least talked about is its
tendency to dull libido by decreasing testosterone levels.

Contraceptive drugs curb the hormone's production in the ovaries and
also raise levels of sex hormone binding globulin (SHBG), a substance
that takes it out of play. But it is unclear how common problems are
in pill users. Until now, any sexual dysfunction, including loss of
libido, muted or non-existent orgasms or painful intercourse, was
thought to be reversible when women stopped taking the drug.

Irwin Goldstein, Claudia Panzer and their colleagues at Boston
University studied 125 young women who attended a sexual dysfunction
clinic. Sixty-two of them were taking oral contraceptives, 40 had
previously taken them and 23 had never taken them. The team measured
levels of SHBG in the women every three months for a year, and found
that in pill users they were seven times as high as in women who had
never taken them. Levels had declined a bit in women who had stopped
taking the pill, but remained three to four times as high as in those
who had never taken it, the researchers told a meeting of the American
Association of Clinical Endocrinologists in Washington DC last week.
"There's the possibility it is imprinting a woman for the rest of her
life," says Goldstein



Heroin addiction gene identified and blocked
15:00 31 May 2005
NewScientist.com news service
Jennifer Viegas

Scientists have not only identified a critical gene involved in heroin
addiction relapse, but they have also successfully blocked it,
eliminating cravings for the drug.

The study was conducted on heroin-addicted rats. But the researchers
now think that, within a few years, better treatments will become
available to human heroin users who cannot quit due to insidious
cycles of relapse.

"Many people try to stop taking heroin, but in a few months almost all
of them go back to using the drug," said Ivan Diamond, at the Ernest
Gallo Clinic and Research Center in California, US, and one of the
research team.

David Shurtleff, director of the Division of Basic Neuroscience and
Behavioral Research at the National Institute on Drug Abuse in
Maryland, US, is encouraged by the research. "It will take creativity
and additional research to translate this into usable therapies, but
it does provide hope that we will be able to prevent compulsive drug
seeking behaviour," he told New Scientist.
Reward circuitry

Previous research has indicated that a section of the midbrain called
the nucleus accumbens plays a central role in the "mental reward
circuitry" of animals, such as rats and humans. This circuitry
generates feelings of pleasure in response to drugs, as well as in
response to other things, including food, sex and, in humans, work
accomplishments.

Drugs like heroin, however, seem to over-stimulate the normal reward
process to the point where users value their next fix more highly than
food, water and other essentials. In 2004, a study revealed that
cocaine causes a gene in the nucleus accumbens, called AGS3, to
rapidly encode masses of proteins that are involved in the cravings
and pleasure associated with the drug.

Diamond and his team isolated AGS3 genes and proteins in nucleus
accumbens cells taken from newborn baby rats. After cloning and
studying the cells in the lab, the researchers determined that AGS3's
drug-related functions are most active in the inner nucleus accumbens
core as opposed to its outer shell region.

An AGS3 blocker was then created from a herpes virus. This temporarily
binds to proteins within the reward circuit and blocks the cravings-
pleasure cycle until the virus "washes out" of the body a few weeks
later.
Eliminated desires

Heroin-addicted rats that were trained to give themselves the drug
using a lever were injected with the AGS3 blocker into their nucleus
accumbens after they had gone through a short period of withdrawal. A
small dose of heroin then was administered to each rat.

Normally even such a tiny "taste" of the drug leads to cravings for
more, but the blocker prevented the addiction relapse by eliminating
these desires. The treatment produced no other observed behavioural
side effects.

Diamond told New Scientist that a related treatment could become
available to humans within the next couple of years. His colleague
Krista McFarland, at the Medical University of South Carolina, added
that one of the challenges will be to find a safe method of
administering the blocker to people.






Astronomers find best gravitational wave prospect
15:32 01 June 2005
NewScientist.com news service
Maggie McKee
Two burned-out stars are spiralling towards each other so fast they
may ripple the fabric of space-time more than any other source near
Earth, suggest new observations. A future space mission may detect the
ripples - or gravitational waves - within 10 years.

Massive, accelerating objects such as black holes and the dense
corpses of stars are thought to release gravitational waves as they
orbit each other. This allows them to fall inwards until they
eventually collide and merge - unleashing even more powerful
gravitational radiation.

Though widely theorised, no such waves have yet been detected. But new
observations with the Chandra X-ray Observatory may have identified
the most likely candidate for a future detection. The space telescope
has confirmed previous observations suggesting two white dwarfs - the
burned-out embers of stars like our Sun - are whipping around each
other every 321.5 seconds.

Tod Strohmayer, an astrophysicist at NASA's Goddard Space Flight
Center in Greenbelt, Maryland, US, used Chandra to reveal that the
pair's X-ray emission varies on that timescale - and is gradually
quickening. Strohmayer thinks the emission comes from matter dropping
from one star onto the other, and says the stars may be edging closer
to each other by about 3 centimetres per hour.
Stellar cadavers

The pair, called RX J0806.3+1527, appear to be separated by just 80,
000 kilometres - five times closer than the distance between the Earth
and Moon. That makes them the closest of about 10 known white dwarf
binaries.

"It's either the most compact binary known or one of the most unusual
systems we've ever seen," says Strohmayer. "Either way it's got a
great story to tell." The pair lies just 1600 light years from Earth.

Other, denser, types of stellar cadavers called neutron stars are
thought to be more powerful sources of gravitational waves. But pairs
of these stars are rarer, with only three known. And all three pairs
are at least tens of times further from Earth - and each other - than
RX J0806.3+1527.

That means the nearer white dwarf duo may be the strongest source of
gravitational waves detectable by astronomers. "There are more of the
white dwarf pairs out there," says Matthew Benacquista, an
astrophysicist at Montana State University in Billings, US. "It's
quantity rather than quality."

He says ground-based gravitational wave detectors would be capable of
picking up signals from the apocalyptic final seconds before a pair of
neutron stars collide. But a future US-European space-based detector
called LISA (Laser Interferometer Space Antenna) should be able to
detect gravitational waves with frequencies thousands of times lower
than those of ground-based instruments.
Sore thumb

That means LISA should be able to detect the gravitational waves
leaking from this pair of white dwarfs. The effect should show up as a
small change in the relative spacing of the three spacecraft in the
LISA fleet.

"When LISA searches for gravitational wave sources, this one might
stick out like a sore thumb," says Strohmayer, who presented the
Chandra observations at a meeting of the American Astronomical Society
in Minneapolis, Minnesota, US, on Monday.

"It is currently the best candidate," agrees Benacquista, who is
involved in planning for LISA, which could launch around 2012. But he
says yet more massive pairs of white dwarfs - producing "louder"
gravitational waves - could remain to be discovered.

That is because astronomers can only detect light from systems where
one white dwarf is dumping matter onto the other. "There may be
something that hasn't yet begun transferring mass and so we simply
can't see it," he told New Scientist.


BEST ONE!!!!!!!!

Trust me, I'm spraying you with hormones
18:00 01 June 2005
NewScientist.com news service
Andy Coghlan
Giving people a whiff of a key chemical can make them more inclined to
trust strangers with their cash, a new study reveals. Just three puffs
of a nasal spray containing a hormone called oxytocin increased the
chance that people would part with their money.

The research centred around a game in which an "investor" player gives
part or all of his money on blind trust to an anonymous "trustee"
player who earns interest on the combination of his own money and the
invested sum. But the investor is told there is no obligation for the
"trustee" to give any money back at all - they risk losing any money
they choose to invest.

Michael Kosfeld at the University of Zurich, Switzerland, who led the
study found that investors gave away their money far more willingly if
they had sniffed oxytocin than if they had sniffed a placebo. But this
extra willingness disappeared when the trustee's role was
computerised, rather than carried out by another human, confirming
that the effect was interpersonal, and not simply a general
willingness to gamble.
Overcoming shyness

Kosfeld speculates that the hormone reduces people's aversion to
betrayal, overcoming an unwillingness to initiate interaction with
strangers. This matches observations in animal studies. "It helps
animals to approach one another, which is a parallel with trust in our
game," he says.

Kosfeld's team sees great potential for the hormone in the treatment
of people who are excessively shy or withdrawn. "We're hoping that if
you use oxytocin as a companion to psychotherapy, it could have some
positive effects," he says.

But could it be used to con people? Kosfeld doubts it, because it
takes nearly an hour for the hormone to reach the brain. Nor would it
be easy to make people "sniff" something unfamiliar, and it is not
known whether it would work through a spiked drink.

Oxytocin is more conventionally used to help induce labour in pregnant
women and assist breastfeeding in mothers.