Disease model

Introduction

In the very beginning of the project, we focused on the duodenum and the iron absorbed by it. In order to determine if a flush treatment strategy was viable, we first had to model the behaviour of the duodenum regarding iron absorption.

Observations

60% of iron absorption takes place in the duodenum, the last 40% in the jejunum. The duodenum is located at the upper intestines, right after the stomach, and is usually 300mm long.

A healthy person absorbs about 10% (2mg a day) of the daily iron uptake, while a hemochromatosis person's absorption varies between 50% and 100% of the daily iron uptake^[1].

Goals

Our goal in this part of the model is to create a generic duodenal iron absorption model so that:

• We can have a realistic base for the Final flush treatment model
• The model can can be reused in the future

Assumptions

• Our bacteria don't settle in the duodenum
• No regulation in the patient's iron absorption
• Constant iron flow
• Homogeneous fluid
• The bacterial quantity is constant
• The bacterial natural absorption is insignificant compared to the chelation
• The patient ingests 20mg of iron per day (Guideline Daily Amounts)

Materials and methods

The duodenum is considered as a cylinder in which a homogeneous fluid flows. So, this model is divided into three steps: the filling of duodenum, the steady state flowing step and the emptying.
This model has two variables : the iron disolved in the middle (S) and the absorbed iron (A).
We considered the chyme arrives in the duodenum at a constant rate. S has a linear component Sp which represents the pulses. The also are an emptying component and an absorption component.
We assumed a linear absorption and a negative feedback regulation for A.
Finally:

Name	Unit	Description	Reference
α	s-1	Duodenum absorption rate
v	m/s	Chyme's flow average speed	[2]
L	m	Duodenum length	[3]
Sp	mol/s	Iron pulse	[1][2]

Parameters fixing :
We have

Results

Conclusion

Models and scripts

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