Summary HIV - Infektion < Korrekturlesen < Englisch < Sprachen < Vorhilfe
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(Frage) überfällig  | | Datum: | 16:12 Di 16.06.2009 | | Autor: | xPae |
Guten Tag,
muss ein Summary über mein Vortrag abgeben. DAher ist es kein wirkliches Summary( kein Text als Grundlage, mehrere Quellen -> keine direkte Quellenangabe am Anfang)
Wenn jmd lust hat ein paar Informationen über HIV zu bekommen und auch noch ein bisschen schlechtes englisch korrigieren will ist er herzlich eingeladen :D
hier der text , vielen dank gruß xPAe
Summary
In the following text Im going to give you some information about the human immunodeficiency virus, especially about the transmission, the structure and genome, how the virus enters a cell and the Epidemiology.
The virus was first recognized in 1981 by Francoise Berré-Sinaussi and Luc Montagnier.
HIV is a lentivirus and a member of the virus-family: Retroviridae. It can effect acquired immunodeficiency (AIDS). The Virus has a diameter of 120nm what is tall for a virus but to compare it to a red blood cell it is very small (60 times smaller). On the surface of the virus there is one glycoprotein-complex (gp120 and gp41). This complex enables the virus to attach the target cells. In the capsid, a shell of viruses consists of several proteins, there are two single RNA-strands. The genome enfolded 9 genes, encoding 19 proteins. The most important ones are reverse transcriptase, proteases, ribonuclease and integrase. The glycoprotein-complex bound on the CD4-Receptor followed by fusion of the viral envelope with the CD4+ cell. On this way the RNA and the viral enzymes enter into the cell. The viral RNA strand is transcribed into DNA by reverse transcriptase. This process is very defective and can result mutations of the DNA. (Drug resistance) The DNA is integrated into the host DNA by the enzyme integrase. The host cell transcribes the viral DNA into mRNA (nucleus; with splicing) and translates it in proteins.(Cytoplasm) One of these proteins is Rev it goes back into the nucleus and binds to viral mRNA and allows unspliced RNAs to leave the nucleus which is needed for a new virus particle. The RNA is packaged into a new particle by the Gag-protein. The new virus leaves the CD4+ cell.
HIV attacks the human immune system. It infects the helper T cells, macrophages and dendritic cells. (CD4+ cells) CD4 is a protein, expressed on the surface of T helper cells etc. and it activates a lot of biochemical processes in the CD4+ cells. All in all it is very important for the human immune system. If the CD4+ concentration decline below a critical level the cell-mediated immunity is lost, and the infected person is more vulnerable to infections. These infections are the reason why the people die. To give some examples for typical diseases: tuberculosis, herpes, pneumonia and Epstein-Barr-Symptoms.
There are three ways of transmission: First the sexual route. The majority of HIV infections are caused by unprotected sexual relations. The risk of an Infection by female-to-male is 0.04% per act, risk of male-to-female transmission is 0.08% per act. In low income countries the risk is 4-10times higher than in high-income countries. Using a condom reduces the risk of transmission by 85%.
The second route is: blood to an open wound contact. If infected blood comes into an open wound the 9.000 of 10.000 people were transmitted. This is very important for drug-users, hemophiliacs and recipients of blood transfusions.
The last route I want to mention is: Mother to child. The virus can be transmitted to the child during pregnancy, at child birth and via breast feeding.
At least I want to give you a short overview about the Epidemiology. The World Health Organization evaluate that more than 25 million people were killed by AIDS since 1981.In 2007 2.5 million people were infected with HIV. In the same year 2.1 million died because of AIDS. In Germany 59.000 people lives with a HIV infection, 80percent of these are men.
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(Mitteilung) Reaktion unnötig  | | Datum: | 16:20 Do 18.06.2009 | | Autor: | matux |
$MATUXTEXT(ueberfaellige_frage)
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