PHAR1101 Lecture Notes - Lecture 10: Salmonellosis, Candidiasis, Sarcoma
Viral Challenge: the HIV epidemic and beyond:
AIDS – a modern catastrophe begins:
Jan 1981 – UCLA hospital
- Dr. Gorrlieb sees very ill 31 y.o gay man (previously healthy)
- Fever, wasting, viral infections, fungal infection (lung), mucocutaneous ulcers, etc.
- More patients soon referred.
AIDS complications – infections:
Pneumonia (PCP) – major cause of death in untreated AIDS
Tuberculosis (TB) – key cause of death in 3rd world AIDS
Cytomegalovirus (CMV) – dormant CMV reactivates to damage eyes, GI-tract and lungs.
Salmonellosis – causes fever, diarhhoea and GI pain
Candidiasis – causes yeast infection of mucous membranes (mouth, vagina).
Crytococcal meningitis – yeast infection → inflammation of brain and spinal cord
(meningitis)
- Tumours
Kaposi’s sarcoma – tumour of blood vessel walls,
- Appears as pink or red lesions on skin and mouth
- Also affects GI tract and lungs.
Lymphomas – origiate i WBC’s and lymph nodes (swelling in neck, armpit or groin).
- Other:
Wasting syndrome – loss of 10% of body weight
- Often accompanied by diarrhea, chronic weakness and fever
AIDS dementia – extensive neuronal loss in brain regions controlling memory, speech, movement,
planning.
- Symptoms include confusion, forgetfulness, depression, unstable walking, diminished cognitive
function.
Global origins and impact of AIDS:
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AIDS pathogen likely originated in simian virus transfer from primates
- 50-100 years ago (possibly late 17th century)
1959, earliest seropositive human blood (Congo).
Dominant mode of transfer via sex (hetero and homosexual)
2015 AIDS estimates in adults and children:
People living with HIV – 36.7 million
New HIV infections in 2015 – 2.1 million
Deaths due to AIDS in 2015 – 1.1 million
Factors assisting the spread of HIV
- Migration of carriers into cities
- Poverty, prostitution,
- International travel
- Risky sexual behavior
- Intravenous drug use
- Receipt of blood and blood products.
Historical interest in cancer-induction by viruses:
What is a retrovirus?
- Member of retroviridae family
- Related retroviruses infect sheep, horses, goats, cats,
cows etc.
- All express reverse transcriptase.
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- RT converts RNA genome into DNA with infected cells
- DNA enters nucleus and integrates into genome
HIV (human immunodeficiency virus)
Virus diameter – 100-120nm
Virus envelop and matrix enclose the capsid which contains RNA genome
Glycoproteins (sugar-decorated proteins) on the virus surface (gp120 and transmembrane
gp41) form studs or spikes
Gp 120 is major binding partner with receptors on infected cells
HIV immune system damage
Kills T cells and macrophages which express CD4 glycoprotein on cell
surface (CD4+)
Slow depletion of t-helper lymphocytes cause immune deficiency
Loss of T cells means ody a’t fight off otherwise rare ifetios
(opportunistic infections)
Persistent replication of virus throughout body
Also impaired tumour immunosurveillance.
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Document Summary
Dr. gorrlieb sees very ill 31 y. o gay man (previously healthy) Fever, wasting, viral infections, fungal infection (lung), mucocutaneous ulcers, etc. Pneumonia (pcp) major cause of death in untreated aids. Tuberculosis (tb) key cause of death in 3rd world aids. Cytomegalovirus (cmv) dormant cmv reactivates to damage eyes, gi-tract and lungs. Salmonellosis causes fever, diarhhoea and gi pain. Candidiasis causes yeast infection of mucous membranes (mouth, vagina). Crytococcal meningitis yeast infection inflammation of brain and spinal cord (meningitis) Kaposi"s sarcoma tumour of blood vessel walls, Appears as pink or red lesions on skin and mouth. Lymphomas origi(cid:374)ate i(cid:374) wbc"s and lymph nodes (swelling in neck, armpit or groin). Wasting syndrome loss of 10% of body weight. Often accompanied by diarrhea, chronic weakness and fever. Aids dementia extensive neuronal loss in brain regions controlling memory, speech, movement, planning. Symptoms include confusion, forgetfulness, depression, unstable walking, diminished cognitive function. Aids pathogen likely originated in simian virus transfer from primates.
