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ENFERMEDAD SEXUAL
Tags : SIDA |
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Affichage : 19546
Durée : 167 s |
| HIV Replication 3D Medical Animation |
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It is a very excellent animation which explains
the hiv replication very clearly.
For free download of this video please visit my
webpage
http://rufusrajadurai.wetpaint.com/
And other 3D animation videos visit
http://rufusrajadurai.wetpaint.com/page/3D+Medical
+Animation+Library
Regards,
Dr.Rufus
The Lyrics of this video is here
Targeting HIV replication
The replication of HIV 1 is a multi-stage process.
Each step is crucial to successful replication and
is therefore a potential target of antiretroviral
drugs.
Step one is the infection of a suitable host-cell,
such as a CD4-positive T-lymphocyte.
Entry of HIV into the cell requires the presence
of certain receptors on the cell surface, CD4 --
receptors and co-receptors such as CCR5 or CXCR4.
These receptors interact with protein-complexes,
which are embedded in the viral envelope.
These complexes are composed of two glycoproteins:
an extracellular gp 120 and
a transmembrane gp 41
When HIV approaches the target cell gp120 binds to
the CD4-receptors. This process is termed
attachment.
It promotes further binding to a co-receptor.
Co-receptor binding results in a conformational
change in gp120.
This allows gp41 to unfold and insert its
hydrophobic terminus into the cell membrane.
Gp 41 then folds back on itself.
This draws the virus towards the cell and
facilitates the fusion of their membranes.
The viral nucleocapsid enters the host cell and
breaks open releasing two viral RNA-strands and 3
essential replication enzymes:
Integrase, Protease and Reverse Transcriptase.
Reverse Transcriptase begins the reverse
transcription of viral RNA.
It has two catalytic domains:
The Ribonuclease-H active site
And the polymerase active site
Here single stranded viral RNA is transcribed into
an RNA-DNA double helix. Ribonuclease- H breaks
down the RNA.
The polymerase then completes the remaining
DNA-strand to form a DNA -- double helix.
Now Integrase goes into action.
It cleaves a dinucleotide from each 3-prime end of
the DNA creating two sticky ends.
Integrase then transfers the DNA into the cell
nucleus and facilitates its integration into the
host cell genome.
The host cell genome now contains the genetic
information of HIV.
Activation of the cell induces transcription of
proviral DNA into messenger RNA.
The viral messenger RNA migrates into the
cytoplasm where building blocks for a new virus
are synthesised.
Some of them have to be processed by the viral
protease.
Protease cleaves longer proteins into smaller core
proteins.
This step is crucial to create an infectious
virus.
Two viral RNA-strands and the replication enzymes
then come together and core proteins assemble
around them forming the capsid.
This immature particle leaves the cell acquiring a
new envelope of host and viral proteins.
The virus matures and becomes ready to infect
other cells.
HIV replicates billions of times per day
destroying the hosts` immune cells and eventually
causing disease progression.
Drugs which interfere with the key steps of viral
replication can stop this fatal process.
Entry into the host cell can be blocked by fusion
inhibitors for example.
Inhibition of reverse transcriptase by nucleoside
inhibitors or by non-nucleoside Reverse
Transcriptase- inhibitors is part of standard
antiretroviral regimens.
The action of Integrase can be blocked.
Protease inhibitors are also part of standard
antiretroviral therapy.
Each blocked step in viral replication is a step
towards better control of HIV disease.
Script, Storyboard, Art Direction by: Frank
Schauder, MD
Animation: MACKEVISION
Publicity: Dr.Rufus Rajadurai.MD.,D.DENS.,
Tags : hiv replication medical animation 3d aids virus dr rufus rajadurai ccr5 cxcr4 cd4 |
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Affichage : 349833
Durée : 313 s |
| Notre monde, ensemble contre le VIH |
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Durant cette décennie, le VIH-sida fera plus de
victimes que toutes les guerres et catastrophes
réunies depuis cinquante ans. Depuis le début de
l'épidémie, 25 millions de personnes sont
décédées et plus de quarante millions vivent
avec le VIH. La Fédération internationale est
engagée dans la lutte contre le VIH depuis le
milieu des années 1980. Avec ses 100 millions de
volontaires, elle est en mesure de jouer un rôle
essentiel dans la coordination et le soutien des
efforts locaux visant à combattre la pandémie.
Pour en savoir plus :
http://www.ifrc.org/fr/what/health/hivaids/index.a
sp
Année : 2007
Durée : 11 minutes 11 secondes
Tags : Croix Croissant Rouge Internationale IFRC Catastrophes Secours Préparation Santé Assistance Volontaires Humanité |
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Affichage : 1924
Durée : 671 s |
| VIH |
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Un video sobre el panorama del sida mundial en la
actualidad
Tags : VIH SIDA AIDS HIV |
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Affichage : 5040
Durée : 154 s |
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