GASTRIC ULCERS

1
GASTRIC ULCERS!

• Ellen Griffes, Meg Sutton,
• Dave Goerig, Colin Wahl

2
THE PROBLEM

• Gastric ulcers conditions in the stomach
  resulting in cell damage or cell death, and
  eroding the stomach wall
• Proposed causes
• Prolonged and/or high does aspirin therapy
• Helicobacter pylori infection
• Stress

3
Anatomy of the stomach lining

• The target tissue site for gastric ulcers is the
  mucosa layer of the stomach.
• The mucosa consists of a single layer of
  epithelial cells, connective tissue that holds
  down the epithelial cells and a thin layer of
  smooth muscle.
• It is the secretory cells in this layer of the
  stomach that produce mucus that is used for
  protection.
• If this mucus is destroyed in any way from a
  portion of the stomach, an ulcer is more likely
  to form within the mucosa layer.

4
The danger of aspirin

• Aspirin inhibits the arachadonic acid cascade
  that produces the enzyme cyclooxygenase 1
  (COX-1).
• COX-1 is used in the production of prostaglandins
  which produces the mucus that protects the
  stomach.
• Without this protection, the mucosa weakens and
  becomes more susceptible to invading bacteria.

5
Helicobacter pylori infection

• H. pylori uses enzymes that produce NH3 (ammonia)
  that then combines with H in the stomach to
  reduce acidity
• Protection
• Allows attachment
• H. pylori adheres to the epithelial cells by
  binding to membrane associated lipids and
  carbohydrates.

6
More about H. pylori

• 2/3 of the worlds population is infected with the
  bacteria
• Gastro-oral and fecal-oral are the means of
  transmission
• Can be treated with antibiotics, although
  resistant strains of H. pylori have been found in
  the UK.

7
The myth about gastric ulcers!

• Stress is NOT thought to be a cause of peptic
  ulcers anymore.
• A high stress level may help sustain existing
  ulcers or make a person more susceptible to them.

8
Active ulcers are

• POSITIVE FEEDBACK MECHANISMS!
• H. pylori infection leads to ulcer formation (as
  described earlier)
• An ulcer formation weakens the stomachs ability
  to maintain an acidic environment.
• This is because of the increased production of
  ammonia by H. pylori (or an increasingly basic
  environment), which allows the bacteria to
  continue to embed into the walls of the stomach,
  increasing the size of the already active ulcer.

9
ANALOGY

• Your stomach is your house
• H. Pylori are burglars lurking in your
  neighborhood
• Your house contains an alarm system, controlled
  by Cyclooxygenase Sensors
• Forgetting to lock your doors is equivalent to
  frequently taking aspirin or Ibuprofen.
  Eventually the burglars (i.e. H. Pylori) will
  enter your unlocked home and turn off the
  cyclooxygenase sensors.
• This weakens protective barriers around the house
  (i.e. the mucosa lining) and the burglars can
  destroy your home.
• Burglars continue to destroy the house by
  depleting the walls adornments (i.e. ULCER!!!)
  and further disrupting the nature of the house

10
QUESTIONS???