It is therefore unclear whether the observed modulation of immune mediators was caused by a single component or several.
The problem with investigating mediators in single treatment designs is that no evidence can be found that changes in the mediator are caused by the active treatment and not by other factors (such as passage of time).
The second hit is caused by mediators in the blood transfusion that activate the endothelial cells and pulmonary neutrophils, resulting in capillary leakage and subsequent pulmonary edema [ 2].
The oedema evoked by 1% solution of carrageenin is caused by the mediators of inflammatory process such as histamine, serotonin, interleukins, kinins, and prostaglandin [ 28, 30].
It is known that the systemic response during sepsis is caused by proinflammatory mediators such as interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα).
This event is caused by the release of several inflammatory mediators, such as histamine, serotonin, bradykinin, and prostaglandins [ 39].
If the false-negative 4DST uptake was regarded as one of the reactive features from the surroundings, it might be caused by inflammatory mediators such as chemokines, cytokines, and prostaglandins associated with cancer-related inflammation[41, 42].
It remains to be investigated whether the observed effects result from direct actions of translocated particles or specific components (e.g. PAH, metals, VOC) carried on the surface of these particles (Donaldson et al. 2005), or whether they are caused indirectly by mediators released from respiratory tract and/or the blood (Peters et al. 2006).
Chronic diseases influence physical function but could be both a confounder and a mediator since a chronic disease could be caused by the exposure, or morbidity could influence the duration and intensity of exposure in working life.
5 These metabolic abnormalities are caused by both humoral inflammatory mediators (such as cytokines) and of tumor origin.
