Sat, Feb 11 2012

HIV transmitted during sex may hold clues to infection

Mon, Aug 23 2010 13:02 CET 3650 Views 1 Comment
HIV transmitted during sex may hold clues to infection

An archive photo of a volunteer dressed as a condom during a 2003 AIDS awareness event in Bulgaria.

Photo: Julia Lazarova

A new study finds the AIDS virus circulating in the blood may be very different from the virus that’s transmitted during sex.  And this could have implications in the search for an effective vaccine or microbicide.

University of North Carolina School of Medicine researchers at Chapel Hill say HIV may undergo changes in the genital tract of men.  As a result, the virus contained in semen could hold clues about how to block infection.  More research is needed, however.

Why important

"Most of what we know about HIV is based on analysis of virus that’s in the blood.  And much of the transmission that goes on goes from men to women or men to men.  But the male genital tract, male seminal tract, is involved in those transmissions," says Ron Swanstrom, professor of biochemistry at UNC and the senior author of the study.

"Anything that makes the virus different in semen, which is the site of the transmitted virus, becomes important to understand just to find out if it’s relevant to the transmission event," he adds.

Do researchers know why HIV can change in the seminal tract?  "That’s the big question for us," he says, "and no."

It could be one of two reasons.

Swanstrom says, "There’s a phenomenon known called the founder’s effect where…by chance it’s one thing that gets started and it grows from that….  So it could be just by luck that one or a few viruses get established in the seminal tract and grow out .  In which case presumably there won’t be any differences in terms of the biology of the virus compared to what’s in the blood."

On the other hand, there’s another, more important possibility.

"There could be some selective pressure.  That the virus that grows in the seminal tract has some other different set of circumstances that it deals with and has to adapt to that environment.  And therefore, it’s a little bit different than what’s in the blood," he says.

What’s the difference?

Much of the time HIV in the semen and HIV in the blood may not differ at all.  But other times there may be two different scenarios.

"One virus or a couple of viruses seem to take off over a very short period of time and represent a significant fraction of the virus in the semen.  We don’t know why that happens, but it’ll be a much less complex population.  The population of the blood is very complex genetically.  The viruses are all kind of different from each other.  Suddenly the semen looks much more homogeneous," he says.

Those particular viruses, however, disappear fairly quickly.  Another possibility, he says, is that the virus gets established in the seminal tract and eventually becomes separated from the HIV population in the blood.

"That’s when we see this strong compartmentalization where the virus is very different.  But again, we don’t know what that difference is at this time," he says.

Vaccines, microbicides

At this stage, it’s unclear whether the finding will affect vaccine and microbicide research.  But Swanstrom says, "If this is the pool of viruses that are being transmitted, then it’s really the virus that we want to understand the most about."

He cautions that while the differences can be seen at the genome level, they may not have any biological difference from the HIV in the blood and therefore won’t behave any differently.

"But if they do confer some special property, then we certainly need to know about that. If we were really lucky, it might help inform us on either a vaccine or a more efficacious microbicide," he says.

It’s just a different kind of virus

"I think that’s fair to say.  I’ve been a virologist for a long time and probably what’s different about HIV is that it grows constantly in the host.  And this is also true for HCV (Hepatitis C Virus)."

The biochemistry professor says these are special viruses in that "they know how to survive in the face of our immune system.  For HIV it’s always evolving.  The virus is growing every day."

The HIV lifecycle is only about a day long.  "So 365 times a year it divides.  It grows.  If you think about that in terms of generations and how long it would be to have 365 generations of a person, that gets compressed into every year for HIV.  And whatever the host is able to throw at it, it evolves away from it.  And so there’s this titanic battle that goes on constantly between the virus and the host," he says.

The next step is to clone the HIV found in the semen and study it further to learn whether its difference will make a difference in the search for better treatment or a cure.

Source: VOANews.com

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Comments

Anonymous pshela spee Tue, Aug 24 2010 10:09 CET

HURT OF CONDOM
WHICH USED AS CONTRACEPTIVE
TO PREVENT PRAGNANCY IN
WOMEN
_______________________

When the man using
CONDOMS
As contraceptive the woman
Become mad and crazy.
this duo to the semen of
Man is remaining In the CONDOMS
And it was not ejaculated and dropping in
Vagina of women there is not sweet taste for
Sex meeting .
Like that you are drinking tea or coffee with out
[...]

Read the full comment Sugar the coffee or tea is not sweet it is bitter.

Semen
Of man is like Sugar it make the coitus and
Sex meeting sweet to woman
The sex meeting
Sweet With out
CONDOMS
When man is not Using
CONDOMS
In sex meeting with woman the
Semen of man will Ejaculated and dropping and
Falling in vagina of Woman then the semen is
Absorbed by vagina wall and inter the blood
Circulation and reached the brain
Then the women mind become in a convenience
Mood and good feeling she is not be a Madden Or Crazy woman
______________________

ADVICE FOR YOU
_______________________
To good enjoy and pleasure in your sexual live
And good ERECTION of your CLITORIS i give
You this ADVICE

STOP

Practice reading and writing
Because practice reading and writing
Loosening and lowering the SEXUAL ability and power of you.
GO TO LIVE IN Villages and forestry far from cities and towns
Practice READING and WRITING make you unusual
Woman or SADOMITE (SODOMY) women..
_
_________________________________

SO WE HAVE NEW METHOD FOR
CONTRACEPTION

--------------------------------------------------------------------------------------------------

BARLEY AS CONTRACEPTIVE AND
SEX TONIC FOR MEN AND WOMEN
___________________________

BREAKFAST
* Barley loaf - bread
* Margarine
* Jam
* Tea or coffee
________________________

LUNCH
* Barley loaf - bread
* Grill ham
* Salad - (Cucumber, celery, Pepper, lettuce(
* Pickly - mayonnaise
* Pepsi cola
______________________________

DINNER
* Barley loaf - bread
* Fried egg in vegetable oil - With out shaking the yolk
* Prawns
* Oyster
* Shrimp
* Salad - ( Cucumber, celery, pepper, lettuce (
___________________________________

IT IS FORBIDDEN TO EAT THE
Following FOOD cause it increase
Fertility in WOMEN and MEN
-----------------------------------------
* RICE
* HONEY
* FRUITS = (DATE - GRAPE - FIG - APPLE -
APRICOT - BANANA - PEACH ........etc)
* OVINE MEAT (SHEEP)
* BOVINE MEAT (COW)
* FISH
_____________________________________________________
The statistical indication of Successfulness of this method is finding Out in population of
CHINA
Cause they depend on RICE since old or ancient times
_______________________________________


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