T2 relaxation time measurements in the brains of scalded rats

This study aimed to evaluate the T2 relaxation time of the brain in severely scalded rats using a magnetic resonance （MR） T2 mapping sequence, and to investigate the correlation between T2 relaxation time and plasma glucose level. Twenty-eight Wistar rats were randomly divided into the scalded group （n = 21）and control group （n = 7）. Magnetic resonance scans were performed with T1WI, T2WI, and T2-mapping sequences in the scalded group; the scans were performed 1 day prior to scalding and 1, 3, 5, and 7 days post-scalding; in addition, identical MR scans were performed in the control group at the same time points. T2-maps were generated and T2 relaxation times were acquired from the following brain regions： the hippocampus, thalamus, caudate-putamen, and cerebrum. Pathological changes of the hippocampus were observed. The plasma glucose level of each rat was measured before each MR scan, and a correlation analysis was performed between T2 relaxation time and plasma glucose level. We found that conventional T 1WI and T2WI did not reveal any abnormal signals or morphological changes in the hippocampus, thalamus, caudate-putamen,： or cerebrum post-scalding. Both the T2 relaxation times of the selected brain regions and plasma glucose levels increased 1, 3, and 5 days post-scalding, and returned to normal levels 7 days post-scalding. The most marked increase of T2 relaxation time was found in the hippocampus; similar changes were also revealed in the thalamus, caudate-putamen, and cerebrum. No correlation was found between T2 relaxation time and plasma glucose level in scalded rats. Pathological observation of the hippocampus showed edema 1, 3, and 5 days post-scalding, with recovery to normal findings at 7 days post-scalding. Thus, we concluded that T2 mapping is a sensitive method for detecting and monitoring scald injury in the rat brain. As the hippocampus is the main region for modulating a stress reaction, it showed significantly increased water content along with an increased plasma glucose level post-scalding.

Dynamic changes of serum protein in rats with acute intoxication of Chinese cobra snake venom by proteomic analysis

To elucidate the toxic mechanism of snake venom at the protein level,proteomics technol-ogy was applied to investigate the effect of venom on circulation in the mammalian body.Temporal proteomic analysis was performed to profile the dynamic changes in the sera of Sprague-Dawley rats administered with Chinese cobra venom or saline.Using 8-plex iTRAQ analysis,392 and 636 serum proteins were identified to be linearly upregulated or downre-gulated over time in the low-dose group and high-dose group,respectively.These proteins were mainly associated with the acute phase response pathway,complement system,and liver X receptor(LXR)/retinoid X receptor(RXR)and farnesoid X receptor(FXR)/RXR activation pathways.Compared with the low-dose group,the immune response and integrin pathways were inhibited in the high-dose group,although no obvious effect was observed.With con-sistently higher or lower expression in the high-dose group compared to the low-dose group throughout the whole process of venom poisoning,two proteins,Kininogen-1(KNG1)and orosomucoid 1(ORM1),which are involved in metabolism and immune response,occu-pied a core position in the pathway network and are considered venom dose-dependent biomarker candidates.