Prions are misfolded proteins that cause fatal neurodegenerative diseases in humans and animals. They are not living organisms and do not contain DNA or RNA. Prions work by converting normal proteins into additional misfolded prions, accumulating in the brain and causing spongiform changes. Some diseases caused by prions include kuru, Creutzfeldt-Jakob disease in humans, and mad cow disease in cattle. Prions are highly resistant to heat and chemicals and can survive in the environment for many years. Currently there is no cure for prion diseases, so prevention is key.

1. In the name of Allah, the most
beneficent, The most Gracious and the
most merciful!

2. SUBMITTED TO:
MR.JAVED AHMED
SUBMITTED BY:
M.SHAYAN
PRIONS DISEASE.
shayanadnan00@yahoo.com

3. Introduction to Prions
• Proteinaceous Infections Particle
• Causes TSE (Transmissible Spongiform Disease) which attacks the
central nervous system (the brain).
• Prions are misfolded proteins with the ability to transmit their misfolded
shape onto normal variants of the same protein.
• They characterize several fatal and transmissible neurodegenerative
diseases in humans and many other animals

4. Basic Structure
• The mutated, and
infectious, form is built
from the same amino
acids but take a different
shape.
(NORMAL) (MUTATED)

5. Continue…
(NORMAL) (MUTATED)

6. Differences From Bacteria & Viruses
• Prions do not contain nucleic acid; they don’t have DNA or RNA.
• They are extremely resistant to heat and chemicals.
• Prions are very difficult to decompose biologically; they survive in soil
for many years.

7. PRIONS
• Infectious proteins-proteins which cause disease
• Discovered by Prusiner in 1982 in Scrapie
(neurological disease of sheep)
• Prusiner won the Nobel Prize in Physiology or
Medicine in 1997 Misfolded/abnormally folded
proteins in animals
• which are pathogenic. Normally folded versions
are non-pathogenic.- Causes the similar proteins to
also misfold

8. PRION MULTIPLICATION

9. PRION DISEASE
• Transmissible Spongiform Encephalopathy in Mammals,
• Bovine Spongiform Encephalopathy(BSE, also known as "mad cow
disease") in Cattle
• Creutzfeldt-Jakob Disease (CJD) in humans.
• All known prion diseases affect the structure of the Brain or other Neural
tissue and all are currently untreatable and universally fatal.

10. HOW PRION ENTER IN OUR BODY
• O – Origin of
PRION
• Contaminated meat
• Digestive Track
• Blood Stream
• S – Spleen
• N – Spleen to Brain
• B – Brain

11. HISTORY OF PRIONS
• In 1730s
• Earliest written record of Scrapie
in English sheep; already
prevalent in central Europe.

12. CONTINUE…
• 1950s
 High levels of kuru appear among the Fore
people of New Guinea.
• 1960s
 Scientists experimentally transmit Kuru and CJD
to chimpanzees, demonstrating the
transmissible nature of these diseases.

13. Mystery of Kuru
• In the 1950s, a district medical officer working in
the highlands of New Guinea observed a fatal
disease among the people of the Fore (FOR-ay)
tribe.
• The Fore people called this sickness kuru, which
means "trembling in fear." After initially becoming
unable to walk,
• victims of kuru lost the ability to swallow or chew.
Drastic weight loss would inevitably lead to death.
• Today we know that kuru is one of several diseases
in humans and animals caused by prion (PREE-on)
proteins.

14. CONTINUE..
• 1980s
 60 people die from
CJD after being
infected by
contaminated surgical
instruments.
 85 people die after
receiving prion-
infected growth
hormone injections.

15. CONTINUE…
• 1982
 Dr. Stanley Prusiner coins the
term "prion" (Proteinaceous
Infectious particle).
 Highly purified PrP-res is shown
to be infectious. He goes on to
win the Nobel Prize in Medicine
in 1997.

16. CONTINUE….
• 1985
 Scientists identify the PrP
gene and discover that
uninfected people produce a
normal form of the PrP
protein.

17. CONTINUE…
• 1986
By the year 2000, nearly
180,000 cattle will become
infected. To stop the
spread, thousands of cattle
are killed.

18. NEURODEGENERATIVE DISEASES
CAUSED BY PRIONS

19. KURU
in Fore tribe of New Guinea , who used to eat dead
human body.
Women and children are high risk.

20. MAD COW DISEASE IN HUMAN
• When cattle brains and other
cattle byproducts infected with
BSE are ingested by humans,
there is a risk of developing the
Creutzfeldt-Jakob Disease

21. HOW PRION ENTER IN OUR BODY
• O – Origin of
PRION
• Contaminated meat
• Digestive Track
• Blood Stream
• S – Spleen
• N – Spleen to Brain
• B – Brain

22. At Present, there is no Cure for the
Creutzfeldt-Jakob Disease
Prevention is the only available
option

24. RESULT

25. CONTINUE…

26. PREVENTION
• Cook the meat thoroughly
• If you are a raiser of cow, pig, sheep or a goat, check the list of the
signs of prion diseases.
• If you think you have the early signs of the disease, immediately consult
to a doctor.

27. DIAGNOSE
• Electroencephalogram (EEG)
 record the brain’s electrical pattern
which can be particularly valuable
because it shows specific type of
abnormality in prion proteins
Magnetic Resonance Imaging
(MRI)
 reveals the characteristics patterns of brain
degeneration
that help diagnose PrPSc
• .

28. CONTINUE…
• MRI, PET and CT scans of the brain and body.
• Samples of fluid from the spinal cord (called a
spinal tap)
• Electroencephalogram, which analyzes brain
waves.
• Blood and urine tests.

29. EARLY SIGNS
• Depression / anxiety
• Insomnia
• Dizziness
• Altered mood
• Unusual behavior
• Tingling part of the body

30. LATER SIGNS
• Develops dementia
• Loss of coordination
• Visual disturbance

31. References!
1) McKintosh, E. et.al, 2003. Prion Diseases
2) Collinge, J., 2001. Prion Diseases of Humans and Animals: Their Causes
and Molecular Basis
3) Belay, E.D., 1999. Transmissible Spongiform Encephalopathies in HUMANS.
4) George-Hyslop P., McLaurin, J., and Westaway, D., 2006. Human Prion
5) Diseases and Protein Misfolding Disorders
6) Veith, N.M., 2008. Cellular Trafficking of the Pathogenic Prion Protein PrPSc and
Phenotypic Characterization of Deletion Mutants in the Hydrophobic Domain
of the Normal Prion ProteinC
7) Marsh, D., 2002. Mad Cow Disease: The Risks to Humans
8) Weissman, C. et.al, 2002. Molecular Biology of Prions
9) Mahmoud, M.K.H., 2009. Studies on Pathogenic Mechanisms of Prion Diseases
and Evaluation of Prion Strains Properties
10) Aguzzi, A., et.al, 2007. Molecular Mechanisms of Prion Pathogenesis