| what are the different sizes of PMs and where to they come from? | PM10 (thoracic) -> construction sites, mining sites, paved roads, farming
PM2.5 (fine) -> forest fires, volcanos, coal-powered power-stations, factories
PM0.1 (ultrafine) -> man-made e.g. cosmetics |
| what do DEPs compose of and how are they generated? | diesel exhaust particles can be found in diesel exhaust along with gases, it consists of a carbon core with metal and organic compounds on the surface, they can form aggregates.
they are generated with the incomplete combustion of fuel. |
| which PMs get where in the lungs when inhaled? | PM10 -> do not get into the lungs, are removed/eliminated in the trachea
PM2.5 -> get to the alveoli
PM0.1 -> get to the alveoli and can be diffused into the blood stream |
| how do PMs activate the local inflammatory response? | 1. the PMs are sensed by PRRs
2. the alveolar macrophages release TNF-alpha, IL-1beta, IL-6, IL-8 and granulocyte macrophage colony-stimulating factor (GM-CSF)
3. macrophages can become antigen-presenting cells
4. alveolar and airway epithelial cells are stimulated to produce chemokines |
| how does the local inflammatory response of the PMs become the systemic inflammatory response? | 1. the macrophages produce granulocyte macrophage colony-stimulating factor (GM-CSF) and IL-1beta, which both stimulate the leukocyte production and release from the bone marrow
2. the macrophages also produce IL-6, which stimulate the liver hepatocytes, leading to a production of C-reactive protein, fibrinogen and antiproteases. it also increases the production of platelets. |
| what are the reactive oxygen species? and are they radicals or non-radicals | radicals: superoxide, hydroxyl, peroxyl, alloxyl
non-radicals: hydrogen peroxide, hypochlorus acid, ozone, singlet oxygen |
| how are hydroxyl radicals generated? | Fenton reaction: hydrogen peroxide reacts with iron or copper
(Fe2+ + H2O2 →Fe3+ + •OH + OH−)
Haber-Weiss reaction; hydrogen peroxide reacts with superoxide
(O2•−+ H2O2 → O2 + •OH + OH−) |
| what defense mechanism protects the body against ROS? | antioxidants, they donate an electron to the radicals to neutralize them |
| what are the most important enzyme antioxidants and what do they do? | catalase: converts hydrogen peroxide into water and oxygen
2 H2O2 → 2 H2O + O2
superoxide dismutase
ROOH + 2 GSH → GSSG + H2O + ROH
glutathione peroxidase: converts superoxide into hydrogen peroxide
O2 - + O2 - + 2H+ → H2O2 + O2 |
| what are the results of oxidative stress? | it can damage cell structures like DNA, cell membranes, proteins, lipids, lipoproteins and it can cause many types of diseases (cardiovascular, renal, neurological, respiratory) |
