Mihyon Song

Post-ischemic hypothermia reduced IL-18 expression and suppressed microglial activation in the immature brain

Inflammation is an important factor for hypoxia-ischemia (HI) brain injury. Interleukin (IL)-18 is a proinflammatory cytokine which may be a contributor to injury in the immature brain after HI. To investigate the effects of post-HI hypothermia on IL-18 in the developing brain, 7-day-old rats were subjected to left carotid artery ligation followed by 8% oxygen for 60 min and divided into a hypothermia group (rectal temperature 32 degrees C for 24 h) and a normothermia group (36 degrees C for 24 h). The IL-18 mRNA was analyzed with real-time RT-PCR, and the protein level was analyzed by Western blot, and the location and source of IL-18 were assessed by immunohistochemistry. The significant increase of the IL-18 mRNA was observed in the ipsilateral hemispheres of the normothermia group at 24 h and 72 h after HI compared with controls, but the level in the ipsilateral hemispheres of the hypothermia group was significantly reduced at both time points, compared with the normothermia group, respectively. The IL-18 protein level in the ipsilateral hemispheres of the normothermia group significantly increased at 72 h after HI compared with controls, however, the protein level of the hypothermia group was significantly decreased, compared with the normothermia group. IL-18-positive cells were observed throughout the entire cortex, corpus callosum (CC) and striatum in the ipsilateral hemispheres of normothermia group at 72 h after HI, however, little positive cells were observed in the hypothermia group. Double labeling immunostaining found that most of the IL-18-positive cells were colocalized with lectin, which is a marker of microglia. The number of ameboid microglia (AM) in the normothermia group was significantly increased in cortex and CC, compared with the number in controls, but there were very few ramified microglia (RM) in these areas. In contrast, the number of AM in the hypothermia group was significantly decreased in cortex and CC, compared with the number in the normothermia group, and there were no significant differences in the number of AM and RM between the hypothermia group and controls. In conclusion, we found that IL-18 mRNA and the protein level were attenuated by post-HI hypothermia and that post-HI hypothermia may decrease microglia activation in the developing brain.

Relationship Between Human Tumor‐Associated Antigen RCAS1 and Gestational Diabetes Mellitus

The human tumor‐associated receptor‐binding cancer antigen expressed on SiSo cells (RCAS1) is considered to play a role in the inhibition of the maternal immune response during pregnancy. The aim of our study was to investigate the expression of RCAS1 protein in the placenta and to compare its concentration in maternal and cord blood sera between normal pregnancies and pregnancies complicated by gestational diabetes mellitus (GDM).

Level of S100B protein expression in the amnion at various gestational ages in the third trimester of normal pregnancies

Background. S100B protein is a unique calcium‐binding protein. Its biological role within the cell populations is not completely defined. Some pathological conditions that develop during pregnancy could affect S100B concentrations in the amniotic fluid, cord blood, and maternal serum. The aim of our study was to assess the correlation between S100B protein expression in the amnion, amniotic fluid and gestational age in the third trimester of uncomplicated pregnancies. Methods. Amnion, amniotic fluid, maternal peripheral and umbilical cord blood samples were collected from healthy women who delivered at 31–36 weeks (n = 17), 37–40 weeks (n = 22), and 41–42 weeks (n = 21). The expression of S100B in the amnion was assessed by immunohistochemistry and real‐time (RT)‐PCR, and its concentrations in amniotic fluid, maternal and cord blood sera were determined by ELISA. Results. The S100B protein expression in the amnion and its concentrations in amniotic fluid, maternal and cord blood sera of patients in the third trimester were not significantly different at various gestational ages. Conclusions. The S100B protein expression in the amnion and the S100B protein concentrations in amniotic fluid, maternal and cord blood do not vary significantly in the third trimester of uncomplicated pregnancies.