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Title: | ARCHIVE-- Topics of Interest to Women, Volume 2 --ARCHIVE |
Notice: | V2 is closed. TURRIS::WOMANNOTES-V5 is open. |
Moderator: | REGENT::BROOMHEAD |
|
Created: | Thu Jan 30 1986 |
Last Modified: | Fri Jun 30 1995 |
Last Successful Update: | Fri Jun 06 1997 |
Number of topics: | 1105 |
Total number of notes: | 36379 |
235.0. "Contraceptive Vaccine" by ARTFUL::SCOTT (Wastin' away again) Fri Oct 07 1988 09:35
Reprinted without permission from Thursday's (10-6-88) Boston Globe:
Success reported in animal tests of sperm vaccine
=================================================
In a study that is viewed as a milestone in contraceptive
research, a team of Connecticut scientists has shown that an
antisperm vaccine is 100 percent effective at blocking conception,
whether used in male or female animals.
The vaccine, called PH-20, is reversible and causes no apparent
side effects. And, since an anti-sperm vaccine does not block
implantation of a fertilized egg in the uterus but makes sperm
incapable of fertilizing an egg, it would, in a human version,
probably avoid the political pitfalls of some other antifertility
approaches, researchers say.
Although other contraceptive vaccines are also under development,
including one called HCG currently being tested in humans in
Finland, Australia and India by the World Health Organization,
none has yet been shown as effective as PH-20, which has been
tested only in guinea pigs.
Still, researchers say, it could be years before an antisperm
vaccine is widely available.
In work to be published today in the British journal Nature,
researchers at the University of Connecticut, led by Paul
Primakoff, injected male and female guinea pigs with a synthetic
version of PH-20, a protein found on the surface of sperm that
helps sperm penetrate eggs.
Although the term vaccine has been used mainly to designate a
substance that stimulates protection against disease, it can also
mean any substance that triggers an immune response.
In vaccination, a foreign protein is injected into the body,
triggering a complex immune response including the formation of
antibodies that can attack that protein. In a high dose in a
vaccine, the body recognizes sperm as a foreign substance.
An attack on sperm
------------------
In addition to contraception, the new research is also likely to
boost research in human infertility, about 2 percent of which is
caused by a misguided immune attack on sperm, in which either the
man's or woman's immune system perceives sperm as foreign and
attacks it.
The injected females produced antibodies, immune system proteins,
against PH-20. When mated with fertile males, none of the
immunized females conceived.
The researchers then showed that in the test tube, the females'
antibodies bound to sperm and kept the sperm from fertilizing
eggs.
The immunized females gradually regained their fertility. Six
months after vaccination, 17 percent were fertile again; by 15
months, 100 percent were.
In the injected males, PH-20 also stimulated an immune response
which attacked sperm in the testes, where sperm is made. None of
the immunized males was able to impregnate fertile females; yet
after the immune response wore off, the males, too, were again
fertile.
And despite the immune attack on the testes, there was no damage
to tissue.
Because the antibodies made against the sperm protein are so
specific, researchers added, they appear safe because they do not
"recognize" or attack any other cells in the body.
Toward a sperm protein
----------------------
While the guinea pig protein itself could theoretically be
tried--and might work some of the time--to prevent conception in
humans, the more likely path, researchers said yesterday, is to
develop a human sperm protein.
That process is under investigation by Erwin Goldberg, professor
of biochemistry, molecular biology and cell biology at
Northwestern University in Evanston, Ill.
Goldberg said yesterday that his team has cloned the human gene
for a key sperm protein call LDH-C-4 (lactate dehydrogenase C-4)
and has produced it through genetic engineering.
They will test it soon as a vaccine in baboons. Goldberg praised
the Connecticut team's work as "quite impressive," adding that it
is all the more remarkable because "there is virtually no support
these days for contraceptive vaccine work."
In an article accompanying today's paper in Nature, R.J. Aitkin
and M. Paterson of the Reproductive Biology Unit of Britain's
Medical Research Council noted, "of all the methods currently
being researched, the engineering of contraceptive vaccines must
be the most exciting."
The PH-20 data, they add, provide "convincing evidence for the
feasibility of developing an effective contraceptive vaccine based
on sperm-specific antigens."
T.R | Title | User | Personal Name | Date | Lines |
---|
235.1 | | ARTFUL::SCOTT | Wastin' away again | Fri Oct 07 1988 09:40 | 5 |
|
Imagine--a unisex method of contraception! The sociological
implications are staggering.
-- Mikey
|
235.2 | AIDS | AKOV12::INNAMORATI | | Fri Oct 07 1988 10:39 | 8 |
| People keep finding more ways of preventing pregnancy but at
the same time why don't they find something that can prevent pregnancy
and stop AIDS at the same time the only cure they have for it is
condoms and most people won't use them becasue it takes away from
the moment.
Picture it you are in the mood and all of a sudden you have to stop
to get up and put on a condom. It takes away from it all.
|
235.3 | correction and comment to .2 | MEWVAX::AUGUSTINE | Purple power! | Fri Oct 07 1988 11:17 | 9 |
| correction to .2
> the only cure they have for it is condoms
Unfortunately, there is no cure for AIDS. Condoms are often used to
prevent AIDS transmission, however. I've heard that getting accustomed
to using condoms can be awkward, but that once over that hurdle,
they're not too bad. And actually, it sounds like they take away from
the moment no more than a diaphragm would.
|
235.4 | | TFH::MARSHALL | hunting the snark | Fri Oct 07 1988 15:03 | 14 |
| re "condoms":
Dennis Miller of Saturday Night Live says:
"Some people say a condom deadens the sensations. I wear two
condoms in my normal life, when I want to make love, I take one off
and feel like a wild man"
/
( ___
) ///
/
|
235.5 | Advances like this could help to reduce abortions. | 25532::STANLEY | What a long, strange trip its been | Fri Apr 28 1989 17:21 | 23 |
| Not a contraceptive vaccine, but worth considering.
From today's Boston Globe:
WASHINGTON - "A Food and Drug Administration advisory committee
voted unanimously yesterday to recommend approval of a contraceptive
that protects a woman from pregnancy for five years when implanted
under the skin.
The substance, called Norplant, comes in the form of six silicone
rubber capsules the size and shape of wooden matchsticks.
Final FDA approval of Norplant, which contains the same
progesterone-like hormone that is found in many birth control
pills, could come in the next several weeks. The implants
could be available about six months after approval.
The 11 member committee found that the new contraceptive is both
highly effective and at least as safe as birth control pills already
on the market. "I think we could say safer", said one committee
member, Paul G. McDonough, a professor of obstetrics and gynecology
at the Medical College of Georgia."
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