This lesson will increase your knowledge of concepts covered in the following TEKS for biology:

1. This lesson will increase your knowledge of concepts covered in the following TEKS for biology: 3.c – Evaluate impact of research on scientific thought, society, and the environment 3.e – Evaluate models according to their adequacy in representing biological objects or events 3.f – Research and describe the history of biology and contribution of scientists. 4.a – Identify the parts of a cell 4.b – Investigate and identify cellular processes including homeostasis, permeability, energy production, transportation of molecules, disposal of wastes, function of cellular parts, and synthesis of new molecule 4.c – Compare the structures and functions of viruses to cells and describe the role of viruses in causing diseases and conditions such as acquired immune deficiency syndrome, common colds, smallpox, influenza, and warts

2. 6.b – Explain replication using models of DNA and RNA 6.c – Identify and illustrate how changes in DNA cause mutations and evaluate the significance of these changes. 10.a – Interpret the functions of systems in organisms 11.a – Identify and describe the relationships between internal feedback mechanisms in the maintenance of homeostasis 11.b – Investigate and identify how organisms, including humans, respond to external stimuli 11.d – Summarize the role of microorganisms in maintaining and disrupting equilibrium including diseases in plants and animals and decay in an ecosystem

3. Previous Lesson Vaccines and Disease Prevention

4. Question: What would happen if terrorists release smallpox in the U.S.? What would the U.S. government do to protect U.S. citizens?

5. Smallpox in the Body Viruses would be inhaled and cause smallpox unless people were vaccinated. Many would die. Based on: Newsweek, October 14, 2002

6. U.S. would try to control • spread of infection with • smallpox vaccine • (made out of cowpox) • The vaccine can be effective if • given within 4 days of initial • infection

7. Question: Rabies is caused by a virus that travels in neurons to the brain and causes death. How does the rabies vaccine (dead rabies viruses) work to protect your pet and you? Dixie

8. The Rabies Vaccine • Vaccination results in immune system response of your pet so antibodies and memory cells formed to fight rabies • Your pet cannot get rabies and therefore cannot transmit rabies to you

9. Question: If you suspect you have been bitten or scratched by a rabid animal, why would doctors give you rabies shots (antibodies for rabies) and not the rabies vaccine (dead rabies viruses)? From: Time, August 23, 1993

10. Microbe with protein coat enters body and starts to reproduce Immune system response to a viral infection takes 7-10 days By injecting antibodies, have protection sooner Macrophages circulate thru body and ingest some of the microbes, alerting Helper T cells by presenting protein coat Helper T cells recognize coat of microbe and alert T and B cells by producing cytokines Killer T cells kill microbe or human cells infected with microbes B cells make antibodies that neutralize microbes Memory T cells remain to provide immunity Memory B cells remain to provide immunity

11. Today’s Lesson HIV Infection and AIDS

12. Overview of Lesson • What causes AIDS? • How is the disease transmitted? • Can we defeat the disease? • AIDS in Africa

13. AIDS • First appeared in the U.S. in the early 1980s in a small number of gay men in California and New York • First cases at NIH for research 1981 • Disease cause- unknown • 1984, previously unknown virus identified, named human immunodeficiency virus or HIV • Reports of AIDS in Africa, Haiti, Europe and Asia

14. HIV infects T cells. Why would HIV need to infect your cells? Dots are HIV in T cell From: Scientific American, October 1988

15. Reproduction of HIV Based on: Mader, S., Inquiry Into Life, McGraw-Hill

16. HIV & Immunodeficiency HIV attacks helper T cells HIV incorporates its genetic material into DNA of helper T cell HIV reproduce in helper T cells HIV emerge from T cells, killing them and reducing the immune system response

17. Microbe with protein coat enters body and starts to reproduce Immune System Response to a Microbial Infection Macrophages circulate thru body and ingest some of the microbes, alerting Helper T cells by presenting protein coat HIV reduces Helper T cells X Helper T cells recognize coat of microbe and alert T and B cells by producing cytokines Killer T cells kill microbe or human cells infected with microbes B cells make antibodies that neutralize microbes Memory T cells remain to provide immunity Memory B cells remain to provide immunity

18. T cells and HIV Based on: U.S. News & World Report, February 12, 1996

19. Normal AIDS • With a deficiency of the immune system, a person • gets many types of infections and cancers • AIDS is actually the last stage of the infection

20. Overview of Lesson • What causes AIDS? • How is the disease transmitted? • Can we defeat the disease? • AIDS in Africa

21. How HIV spread Based on: U.S. News & World Report , February 12, 1996

22. The infection of • Magic Johnson • with HIV (1991) • changed the U.S. • view • Heterosexuals • realized that they • were also at risk of • getting AIDS Based on: U.S. News & World Report, Feb. 12, 1996

23. Modes of AIDS Transmission • Drug needles • Blood transfusion • Homosexual and • heterosexual sex • Mother to offspring

24. Overview of Lesson • What causes AIDS? • How is the disease transmitted? • Can we defeat the disease? • AIDS in Africa

25. Drug Cocktail for HIV Infection AZT, 3TC, Protease drug Based on: Time July 8, 1996

26. AIDS in the U.S. Total cases 886575 37,041 Total deaths 501669 2007 Data from U.S. Department of Health and Human Services CDC, October 2003

27. HIV hides in memory T cells Based on: Time, November 24, 1997

28. From: Newsweek, July13, 1998

29. Overview of Lesson • What causes AIDS? • How is the disease transmitted? • Can we defeat the disease? • AIDS in Africa

30. From: Fort Worth Star-Telegram, June 9, 2000

31. Chimps may have been the source of HIV Where the Chimps Are Based on: Time, February 8, 1999

32. The Pattern of Death 1999 • 2007 Global HIV Statistics • 2.7 million new cases • 30-36 million HIV+ • 2 million AIDS deaths • 30-50 million at risk in China Based on: Newsweek, January 17, 2000

33. How is HIV Transmitted Based on: Scientific American, October 1988 In Africa, the disease is transmitted almost entirely by heterosexual sex

34. A Plague On Many Countries Based on: Newsweek, January 17, 2000

35. The Cost of AIDS Based on: Newsweek, January 17, 2000

36. The Orphans of AIDS Based on: Newsweek, January 17, 2000

37. Next Class Nervous System and Drug Addiction