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Tree Man. Born with an immune system disease Not what causes the growths! Infected by a virus, & couldn’t fight the virus. Dede Koswara Update (Tree Man). In 2008, Dede underwent surgery & doctors cut off 13lbs. of warts/decaying matter using an electric saw.
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Tree Man • Born with an immune system disease • Not what causes the growths! • Infected by a virus, & couldn’t fight the virus
DedeKoswara Update (Tree Man) • In 2008, Dede underwent surgery & doctors cut off 13lbs. of warts/decaying matter using an electric saw. • Unfortunately, Dede’s warts grew back. Click here for Tree Man’s story!
What exactly is a disease? • A condition in which the body is not functioning normally Sickle Cell vs. Normal Red Blood Cells
Cystic FibrosisAffects 70,000 people worldwide • People with CF have a mutation in the gene that produces a protein that controls the components of mucus in the body. • The mutation produces a defective protein, causing the build up of thick, sticky mucus. • Clogs the lungs, leading to life-threatening lung infections • Obstructs the pancreas & stops enzymes from helping the body break down food
What causes disease? • Dietary: deficiency in calories, minerals, or vitamins • Goiter, Scurvy, Rickets
Rickets is the softening of bones in children due to deficiency of vitamin D, phosphorus, or calcium. This can lead to fractures or deformity. This woman has goiter, which causes her neck to become enlarged. It is caused by an iodine deficiency.
Causes of Disease • Genetics: inherited diseases • Hemophilia, Down Syndrome, PKU, High Cholesterol Down Syndrome is caused by an extra chromosome 21 (trisomy 21).
PKU (Phenylketonuria)1 in 10,000 births in the US • PKU is an autosomal recessive disease. It’s caused by a mutation in the gene that produces an enzyme that breaks down phenylalanine. • Phenylalanine 1 of the 20 amino acids. • Without the enzyme, phenylalanine builds up in the blood. This can lead to: • Intellectual disability • Seizures • Other medical problems • If found early, people with PKU can live mostly normal lives, but have to maintain a special diet. May is National PKU Awareness Month.
Causes of Disease • Venoms/Toxins: from plants, snakes, etc. • Sea Snake, Brown Recluse Spider, Poison Ivy Brown Recluse Spider
Causes of Disease • Infection from microorganisms • Bacteria, Viruses, Protists, Fungi, Worms Tapeworms are parasites that can live in our intestines!
History of Disease • Humorism is a theory developed by the ancient Greeks & Romans around 400 BC. • Physicians described the body as having “humors” that needed to be in balance. • Blood • Phlegm • Yellow Bile • Black Bile An excess or deficit of 1 of the humors could influence a person’s health or personality.
Humorism & the Four Temperaments • It was thought that each of the 4 humors represented a distinct personality type. • Blood Sanguine (pleasure-seeking & sociable) • Phlegm Phlegmatic (relaxed & thoughtful) • Yellow Bile Choleric (ambitious & leader-like) • Black Bile Melancholic (analytical & literal) • A perfect balance of each humor would give someone the perfect mix of personalities.
Choleric Melancholic Sanguine Phlegmatic
Humorism • If one part was “bad”, you let it out • Humorism was the most popular idea of the human body until the 19th century! Bloodletting is the withdrawal of small quantities of blood from a patient to cure or prevent illness & disease. Many believed that a woman’s menstrual cycles were meant to cleanse the body of bad humors!
Important People in the History of Disease • IgnazSemmelweis(1844): baby delivery suggestions • Suggested the doctors wash their hands • Reduced mortality from about 35% to about 1% • Dr. John Snow (1854): inspired by Semmelweis • Noticed that Cholera patients all drank water from the same pump from the Thames River • Closed the pump & the epidemic ended in 24 hours
Important People in the History of Disease • Dr. Joseph Lister (1867): sterile surgery • Used carbolic acid to sterilize operating rooms • 50% mortality dropped to 10% mortality Fun Fact! Listerine mouthwash was named after him in 1879!
Important People in the History of Disease • Robert Koch (1880): studied Cholera, Tuberculosis, & Anthrax • First to link a microorganism with a specific disease, proving the germ theory of disease! Dr. Koch is considered to be the founder of Microbiology! Fun Fact! There is a crater on the moon named after him, the Koch Crater!
Koch’s Postulates: method for finding the actual cause of a particular disease • The pathogen should always be found in the body of a sick organism, but not a healthy one. • The pathogen must be isolated & grown in the lab. • When the cultured pathogens are placed in a new host, they should cause the same disease as the original host. • The injected pathogen should be isolated from the second host, & it should be identical to the original pathogen.
Koch’s Postulates • Identify pathogen from sick organism • Grow pathogen in pure culture • Place pathogen in new host (should get same disease) • Isolate pathogen again (should be identical to original host)
Agents of Disease • Bacteria • Viruses • Protists • Worms • Fungi How do they spread? A protist, Plasmodium, causes Malaria!
Spread of Disease – Person to Person • Horizontal: • Exchange of body fluids (blood, semen, saliva) • Airborne disease • Indirect (touching surfaces) • Vertical: mother to child • Syphilis, herpes, rubella
Spread of Disease • Contaminated food & water • Sewage (E. coli, Cholera) • Protists (Amebic Dysentery) • Animal Carriers (Vectors) • Insects (Malaria, Lyme Disease) • Mammals (Rabies) The Rabies Virus is transmitted from an infected animal’s saliva with a bite wound. It causes inflammation of the brain.
Malaria • Mosquito carrying the Plasmodium protist bites a human. • The protist enters the human blood stream & travels to the liver to reproduce. • New protists reenter the blood stream & infect red blood cells. • Another mosquito can be infected when it bites a human & ingests the blood cells carrying the protist.
Epidemiology • The science of how diseases occur & spread • Epidemic: sudden increase of a disease in a region • Pandemic: world-wide epidemic • Endemic: constant low-prevalence of a disease • Outbreak: sudden unexpected occurrence of a disease in a limited demographic The common cold is an endemic caused by a virus!
Interested in becoming an epidemiologist? • These are the questions you might ask: • Who is at risk? • What behaviors put you at risk? • What is the infection rate? • What is the mortality rate? • How is this disease prevented? This is Dr. John Snow’s map of the Cholera outbreak.
Fighting Disease • Prevention first! • Sanitation, washing hands, etc.
Fighting Disease – Sterilization • Sterilization with heat – heat is used to kill bacteria! • In a lab, we use an autoclave to sterilize materials. • Typically set between 121°C – 134°C (250°F – 273°F) • Doesn’t work on all bacteria & viruses; some can survive at even higher temperatures!
Fighting Disease – Disinfectants • Chemicals used to kill bacteria • There are concerns that overuse of antibacterial soaps & detergents will cause bacteria to evolve & become resistant & harder to kill. • What do you think?
Fighting Disease – Food Storage • Refrigeration: cold temperatures slow the growth of bacteria • Boiling: heat is used to kill bacteria • Canning: heat food before placing in a sterile container & sealing for long storage • Usually has an indefinite life span!
Fighting Disease – Food Storage • Pasteurization: heat a food (usually liquid) to kill SOME bacteria, mainly pathogenic microbes • Not the same as sterilization! • Not used on all food, because it affects the quality & flavor Pasteurization is used on wine, beer, & milk to prolong the shelf life.
Fighting Disease • Antibiotics • Destroy the cell walls of bacteria • Prevent growth/replication of bacteria Alexander Fleming discovered Penicillin, a widely used antibiotic, during WWII.
Fighting Disease • Vaccines • Contain a weakened or dead version of a pathogen to trigger an immune response Edward Jenner gave the 1st successful vaccination in 1796 (against smallpox).