Cholera and

Osmosis

Poverty: % under £1 per day

http://www.kenyanview.com/IMG_0865_Nairobi_skyline.jpg

http://www.planetware.com/i/photo/amboseli-national-reserve-formerly-amboseli-national-park-ken132.jpg

Kenya

http://picasaweb.google.com/dmeyer1usa/AfricaTrip2007/photo#5132143011588101730

Mathare Valley outside Nairobi

http://abandoned-orphaned.typepad.com/photos/uncategorized/2007/08/01/matharesewagerut.jpg

Raw sewage flows through the streets.

Imagine you are a doctor in a clinic here. One day a sick young woman enters the clinic……

22 year old female Sudden onset of severe, watery diarrhea Nausea, vomiting Physical exam: dry mouth, low blood

pressure

What are the possible causes? How could you confirm your diagnosis?

http://upload.wikimedia.org/wikipedia/commons/thumb/d/db/Vibrio_cholerae_01.jpg/800px-Vibrio_cholerae_01.jpg

http://microbewiki.kenyon.edu/images/a/a8/V_cholerae.jpg

Under the microscope….

Cholera

http://www.msf.org/source/countries/africa/angola/2006/cholera_tent.jpgWhat is the biggest problem with cholera?

Antiviral medication Antibacterial medication (antibiotics) Salt Aspirin Sugar Water Pepsi

http://www.medicalook.com/systems_images/Digestive_System.jpg

http://visiblehuman.epfl.ch/

Skin

Intestine

Body

Skin

Intestine

Body

Salt

Salt

Salt

Cholera bacteria produce a toxin which makes the epithelial cells secrete salt into the intestine.

Skin

The Body Our Model

SystemBoiling Tube

Dialysis Tube

Intestine

Two Dialysis Tubes per Group

Boiling Tube

= water

= sucrose

Sucrose

Solution

Water

Water

Water

Water

OsmosisOsmosis

OsmosisOsmosis

Net Flow of Water

Sucrose

Solution

Net Flow of Water Net Flow of Water

Salt

Salt

Salt

Salt

Salt

Salt

Salt

Salt

Salt

Salt

Salt

Salt

SaltNet Flow of Water Net Flow of Water

You have to know something about absorption in the epithelial cells of the intestine.

Glucose and sodium are transported together from the intestine, across the cell and into the blood.

Sodium ions glucose

Epithelial cell

blood

intestine

Facilitated diffusion

Active transport

Energy from ATP

Sodium ions

glucose

SaltSugar

SaltSugar

SaltSugar

SaltSugar

SaltSugar

SaltSugar

SaltSugar

SaltSugar

SaltSugar

SaltSugar

SaltSugar

Net Flow of WaterNet Flow of Water

Oral Rehydration Therapy (ORT)

There are still 1.8 million deaths a year from diarrhea – but there would be millions more without ORT

” “”The discovery that sodium transport and glucose transport are coupled in the small intestine so that glucose accelerates absorption of solute and water (is) potentially the most important medical advance this century”

The Lancet, British Scientific Journal - 5th August, 1978

Sushruta, an ancient Indian medical scholar and the father of Ayurveda (1500 B.C.) had prescribed that cholera victims are to be:

"given to drink a profuse quantity of tepid water in which rock salt and molasses have been dissolved; or clarified water combined with rice gruel."

Sushruta Samhita III, verse II