Stability Analysis of a Mathematical Model in Inflammatory Response System Due to SARS Coronavirus Infection

Severe Acute Respiratory Syndrome (SARS) Coronavirus infection in a human body indicated by cytokine response due to an inflammation. The purpose of this research is to construct and analyze a mathematical model of interaction between inflammatory pro-response and anti-response cytokine to predict the dynamic on inflammatory response system, so that the treatment can be optimized. The results obtained in this research describe some dynamics which happen on the cytokines, i.e. the disease-free equilibrium point is asymptotically stable when the basic reproduction number is less than one. In this condition, a patient with initial concentrations of the cytokines around the disease-free equilibrium point will be free of viral infection. The infection equilibrium point is asymptotically stable when the basic reproduction number is greater than one. In this condition, a patient with initial concentrations of the cytokines around the infection equilibrium point will be infected by the virus. Probability of a patient being free of viral infection can increase if the production rate of the cytokines are decreased or the degradation rate of the cytokines are increased.

New Mechanisms of Gastrointestinal Mucosal Injury and Bleeding Induced by Acute Unpleasant Exercise

It remains unclear whether acute unpleasant exercise (AUE) caused by foot shocks leads to gastrointestinal (GI) mucosal injury and bleeding. In this study, we investigated the involvement of inflammatory cytokines in AUE-induced GI mucosal injury/bleeding and oxidative stress by analyzing the expressions of pro-inflammatory (IL-1β, IL-6, TNF-α, and iNOS) and anti-inflammatory (IL-10) cytokines in the hypothalamus and duodenum after foot shocks using PCR. Results showed that the expressions of IL-1β, IL-6, TNF-α, and iNOS were significantly increased following the process, while IL-10 was not activated. These findings suggest that the activation of inflammatory response system (IRS) is closely related to GI mucosal injury/bleeding and oxidative stress induced by AUE caused by foot shocks.