mat Tools Table Window Help AIDS Case Study (17)-2 [Compatibility Mode Mailings
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mat Tools Table Window Help AIDS Case Study (17)-2 [Compatibility Mode Mailings Review View AIDS in a 29-Year-Old Man Jason Mitchell was a 19-year-old student at the University of Oregon who had been in relatively good health throughout his life. He was a distance runner on the cross-country and track teams at the university. In the early part of January 1982 he developed a mild fever, lymphadenopathy sore throat, and excessive fatigue, particularly after completing a training session. Although he was already thin yet fit due to his athletic regimen, he began losing weight. He consulted the athletic trainer who believed that his symptoms were simply those of a driven athlete who was under stress due to academics and the pressure of training for highly competitive meets. Jason was not entirely convinced, so he sought advice from a local clinician. The clinician concluded that the symptoms were indicative of infectious mononucleosis. After three weeks the symptoms went away and Jason felt considerably better. He excelled in cross-country and track and graduated with honors near the top of his class in the spring of 1985. After graduating, he continued to train as a semi-professional runner, preparing for and participating in international meets and races. Seven years after graduating Jason noticed several brown papules on the skin of his feet. After consultation with a physician, the raised lesions were diagnosed as malignant and multifocal neoplasm indicative of Kaposi's Sarcoma. ELISA and western blot confirmed infection with HIV. Additionally, he was shown to have a rapid increase in serum levels of IgG and IgA consistent with clinical signs associated with AIDS, which he was diagnosed as having based on symptoms and laboratory findings. Jason was familiar with HIV infection and its ramifications, but he continued to work out and convinced himself that by doing so the HIV infection and concomitant symptoms of AIDS would go away Several months after his diagnosis he suffered from a bout of pneumonia. Laboratory analysis confirmed that the pneumonia was caused by Pneumocystis carinii, one of the organisms commonly associated with AIDS. An analysis of his blood at this time indicated that he had 300 CD4+ T lymphocytes per microliter of blood (normal 800-1200 cells/L). Within one month, not fully recovered from pneumonia, Jason became infected with Mycobacterium tuberculosis and presented with symptoms characteristic of tuberculosis. The organism disseminated throughout his body, also in keeping with AIDS, and he died several weeks later despite exhaustive treatment with antimicrobials for tuberculosis and zidovudine (AZT), dideoxyinosine and dideoxycytidine for AIDS. At his first consultation for disseminated tuberculosis, blood work showed his CD4+ T lymphocyte count to be 40 cells/mm3 0Explanation / Answer
1) Are there any additional risks for health care workers?
CDC has shown that health care workers are at risk of acquiring the virus via physical contact with cerebrospinal fluid, synovial fluid, or amniotic fluid.
2) Do those infected individuals who have not progressed to AIDS have immune system characteristics that those who do progress do not have?
AIDS non-progressors have Th1 cytokines for example interferon- and interleukin-2. Person who progress to disease produce cytokines such as IL-4, IL-5, and IL-10, which are linked with Th0 and Th2 cells. These cytokines then may cause to immune dysfunction caused with disease. People who do not progress tend to have a very strong HIV-specific, T-helper response also enduring CTL response. At last, they have CD8+ T cells that release chemokines that bind to the coreceptor for macrophages thereby blocking HIV entry.
3) What are some of the structural features of HIV that may be relevant in understanding the virus?
Each virion has 100 nm in diameter. Two glycoproteins are present on HIV-gp120 and gp41. gp120 is the viral receptor for CD4 on host cells. gp41 is with gp120 and crosses the lipid bilayer of the envelope. The nucleocapsid has two proteins called p17 and p24. Most interiors have two copies of single-stranded RNA that make the genome a diploid one, and two molecules of p64 (reverse transcriptase) aslso integrase and a protease.
4) What is the difference between AIDS-related complex and full-blown AIDS?
AIDS-related complex: persons have two or more clinical signs and symptoms such as fever, diarrhea, weight loss, or fatigue also lab results shown that the immune system is not functioning properly. And persons who have full-blown AIDS suffer from a multitude of opportunistic infections, malignancies such as Kaposi's Sarcoma, encephalopathy, and severe weight loss.
5) How did HIV arrive in the human population?
As answer to this question is not known, but earliest documented case was in 1959 in a man from Kinshasa, Democratic Republic of Congo. In the United States, between 1979 and 1981, physicians in New York and Los Angeles were treating g*ay male patients for rare pneumonia, cancer, and other unfamiliar types of illnesses in young men. Also noted that all of the illnesses were rare in people who have healthy immune systems. Researchers isolated a virus called HTLV-III/LAV (human T-cell lymphotropic virus) in 1983 that was determined to be the cause of AIDS. So, the name of the virus was changed to human immunodeficiency virus (HIV).
Because infection with HIV does not result in elimination of the virus by the immune system, does this mean that the immune system does not respond? The answer is no. The initial immune response is actually quite strong and involves both the production of antibody and generation of cytotoxic CD8+ T lymphocyte effector mechanisms. These responses keep the virus at a manageable level even though HIV continues to replicate. Ultimately the virus replicates at a higher rate than the immune system can keep up with, which results in a decrease in CD4+ T cells and an increase in opportunistic infection.
6)What happens to T cells in an individual who is infected with HIV?
When a human is infected with HIV, he or she exhibits increased apoptosis of CD4 and CD8 T cells. CD4 T cell loss is by cytopathicity as a direct result of HIV infection, killing of infected cells by cytotoxic T cells, and bystander cell death of uninfected T cells by apoptosis. Apoptosis of CD4 T cells is a result of intracellular signaling that occurs between the protein gp120 and CD4 molecules in T cells.
7) As of 1999, what are the statistics in terms of how many people are infected with HIV and mortality associated with the virus?
Worldwide, the organism has infected at least 34 million people, 5.4 million in 1999 alone. It has been responsible for the deaths of 19 million people and is expected to ultimately obliterate half of the teenagers in some African countries. In South Africa, 20% of the population is infected with a total of 4.2 million people there that have HIV. In Botswana, 33% of the adult population is infected. Numbers of new infections in parts of Asia, Eastern Europe, and the Caribbean are quickly increasing and may soon match the numbers of the African nations.
8) What is the recommended treatment today for AIDS?
Today treatment involves a combination of drugs: normally two nucleoside analogs [lsuch as AZT and didanosine (ddl) and one protease inhibitor. This type of therapy has resulted in the decrease of viral numbers to such an extent that they cannot be detected. Also, it has resulted in greatly improved health in AIDS patients.
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