Scientists
yesterday announced the first anti-HIV pill to provide effective protection
against the disease that affects 33 million people globally. News (Updated
November 28, 2010)
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By Jeremy Laurance,
Health Editor
Wednesday, 24 November
2010
Scientists
yesterday announced the first anti-HIV pill to provide effective protection
against the disease that affects 33 million people globally.
Gay men at extremely high
risk of HIV who took the oral pill daily cut their risk of contracting the
infection by almost 44 per cent. Aids organisations and researchers said it
heralded a new era of Aids prevention. After the failure of almost 30
large-scale trials of protective therapies, recent positive results for an Aids
vaccine and for a microbicidal gel suggest progress.
"This discovery
alters the HIV prevention landscape for ever," said Jim Pickett of the Aids
Foundation of Chicago. Anthony Fauci, head of the National Institute for Allergy
and Infectious Diseases – which provided two thirds of the $43.6m (£27.6m)
cost of the study – said: "The results are extremely important."
Margaret Chan, director general of the World Health Organisation, said the trial
opened "exciting new prospects".
Mechanism for death of
critical immune cells identified in study
WEDNESDAY, Nov. 24 (HealthDay
News) -- Scientists believe they've discovered how HIV triggers the death of the
immune system's defensive CD4 T cells, which in turn leads to AIDS.
It was believed that most
immune cells that die in people with HIV are not actually infected, a situation
labeled "bystander cell killing." In the new study, the researchers
found that these "bystander" cells die because of a failed or abortive
HIV infection.
"Our study reveals
that the virus actually enters CD4 T cells that are destined to die and that the
virus starts to make a DNA copy of its RNA, a process called reverse
transcription," lead author Gilad Doitsh at the Gladstone Institute of
Virology and Immunology in
"However, this
process does not work well in the majority of these cells and the incomplete DNA
intermediates that accumulate in the [cell's] cytoplasm are sensed and trigger
the cells to commit suicide in an attempt to protect the body," he
explained.
Doitsh and colleagues
also found that the dying CD4 T cells release proteins called cytokines that
cause inflammation and attract healthy immune cells, which prompts more
infection and immune cell death.
"Our findings have
revealed a completely unexpected mechanism for CD4 T-cell death during HIV
infection," senior author and institute director Warner C. Greene said in
the news release. "These results highlight how a natural cellular defense
normally used by the host to repel foreign invaders goes awry in HIV infection,
resulting in a profound depletion of CD4 T cells. If untreated, this process
ultimately causes AIDS."
The study is published
Nov. 24 in the journal Cell.
Wed, Nov 24 2010
The culprit lies in the
powerful drugs that prevent the development of AIDS and have extended the lives
of many HIV patients, the researchers say. They hope the discovery will allow
development of safer antiviral drugs.
The research, published
this month in the Journal of Biological Chemistry, shows HIV protease inhibitor
drugs directly interfere with the way blood sugar levels are controlled in the
body. This leads to insulin resistance, a condition that occurs when the body
produces enough insulin but doesn't use it properly.
Paul Hruz, a professor of
pediatrics and biology at the
This raises blood sugar
levels, a hallmark of diabetes.
"Our lab has
established that one of the effects of these drugs is blocking glucose
transport, one of most important steps in how insulin works," Hruz said in
a statement on Tuesday.
"Now that we've
identified the main mechanism, we will look to develop new drugs that treat HIV
but don't cause diabetes."
Hruz said that the
prevalence of overt diabetes in HIV is about five percent, while 25 percent of
patients have metabolic syndrome, a group of risk factors that occur together
and increase the risk of diabetes as well as heart disease and stroke.
The team is working with
a drug developer to create a new HIV drug that the virus does not develop
resistance to.
Human Immunodeficiency
Virus (HIV) is a virus the human immune system can't rid itself of on its own.
It attacks a key part of the immune system, leaving the body open to infections
and diseases including AIDS, which is the final stage of the disease.
The government estimates
there are more than 56,000 new cases of HIV a year and more than 25 million
people have died of AIDS since it was first recognized by the U.S. Centers for
Disease Control in 1981.
(Reporting by Bruce
Olson; Editing by Jerry Norton)
Tue, Nov 23 2010
(Reuters) - Here are some
global data on HIV and AIDS from the latest update report by the Joint U.N.
Programme on
HIV/AIDS (UNAIDS).
THE GLOBAL PICTURE:
* An estimated 33.3
million people worldwide had the human immunodeficiency virus (HIV) that causes
AIDS in 2009, according to the latest figures issued by (UNAIDS). There were
26.2 million in 1999.
* There were an estimated
1.8 million AIDS-related deaths around the world in 2009.
* One in four AIDS deaths
is caused by tuberculosis, a preventable and curable disease.
* Since the AIDS pandemic
started in the early 1980s, more than 60 million people have been infected with
HIV and nearly 30 million have died of HIV-related causes.
* In 2009, there were 2.6
million new HIV infections, down from 3.1 million in 1999.
* Around 370,000 children
were born with HIV in 2009, bringing to 2.5 million the total number of children
under 15 living with HIV.
* AFRICA &
* An estimated 1.8
million people were newly infected with HIV in sub-Saharan
* There were 1.3 million
AIDS-related deaths in Sub-Saharan Africa in 2009.
* The nine countries in
southern
* South and South East
Asia, home to 60 percent of the world's population, is second only to
sub-Saharan
* In
OTHER REGIONS:
* Some 1.5 million people
in Eastern Europe and
* In Central and
* There were around 2.3
million people with HIV in North America and western and central
SOURCE: UNAIDS/Reuters
(Compiled by David
Cutler, London Editorial Reference Unit; editing by Kate Kelland)
Fri, Nov 26 2010
By Lynne Peeples
All currently available
gel, film and foam spermicides, such as Encare contraceptive inserts and VCF
dissolving vaginal films, contain the compound nonoxynol-9. But researchers
testing a new mixture of spermicidal compounds called C31G found it to be just
as effective at preventing pregnancy, and perhaps even a bit safer to use.
"Spermicides are one
of the least utilized contraceptive methods," lead researcher Dr. Anne E.
Burke of The Johns Hopkins University School of Medicine, in
However, for women who
would rather not depend on a male partner's cooperation in birth control, do not
want to take hormones, or who simply do not have sex all that often, it would be
helpful to have newer and ultimately better spermicide options available, she
added.
Burke and her colleagues
randomly assigned more than 1,500 young, sexually active women to use either a
gel containing C31G or nonoxynol-9 for at least 6 months. Participants were not
told which spermicide they were given and were asked to engage in sexual
intercourse at least four times per month and use the study product as the
primary means of contraception each time.
At six months, pregnancy
rates were 12 percent in both groups, report the researchers in the journal
Obstetrics & Gynecology.
Of course, not all women
were perfect in their use of the spermicide, occasionally applying it
incorrectly or not at all. When the researchers considered only correct and
consistent use of the products, the pregnancy rates dropped to five percent in
both groups.
The aim of the study was
not to determine if C31G was better than nonoxonyl-9, noted Burke, but rather to
see if it was "at least as good." Indeed, it was.
Moreover, participants
reported fewer side effects with the new spermicide compared to the old
standard. Among C31G users, 35 percent experienced at least one side effect --
such as irritation, vaginal or urinary tract infections, or menstrual changes --
over the course of the study compared to 41 percent of those using the
nonoxynol-9 gel.
"There are concerns
with nonoxynol-9, such as vaginal side effects and genital irritation for some
users," she said. "It seems that C31G might offer improvements in
those regards."
Exactly when new
spermicidal products containing C31G might become available is unknown at this
point, senior researcher Diana Blithe of the National Institute of Child Health
and Human Development, in
One of the hopes among
researchers developing new spermicides is that they might address not only the
problems of unintended pregnancy but also sexually-transmitted infections such
as HIV. As a result, C31G has already been extensively tested as a microbicide,
however the current study was not designed to prove such an effect.
Despite showing C31G to
be as effective at preventing pregnancy as existing spermicides, Burke cautioned
that spermicides are still generally less effective than other contraceptive
methods, such as birth control pills or condoms.
"For women who might
prioritize effectiveness above all else," she said, "spermicides may
not be the best choice."
SOURCE: link.reuters.com/kak96q
Obstetrics & Gynecology, December 2010.