Irradiation Injury Temporarily Induces Enhancement of APN/CD13 Peptidase Activity on Aorta-gonads-mesonephros (AGM)-derived Stromal Cells

This study was designed to investigate the expression of aminopeptidase N （APN）/CD13 on intraembryonic AGM stromal cells, and the change of its enzymatic activity after irradiation injury. The expression of APN/CD13 on AGM stromal cells was assayed by RT-PCR and immunihistochemistry. After the stromal cells in AGM region were irradiated with 8.0 Gy of ^60Co T-rays, APN/CD13 enzymatic activity was measured by spectrophotometer at different time points. The result showed that AGM stromal cells strongly expressed APN/CD13. The enzymatic activity of APN/CD13 decreased temporarily after irradiation injury, then increased to higher level 4 h after irradiation, and it returned to the pre-irradiation level 24 to 48 h after the irradiation. The enzymatic activity of APN/CD13 was temporarily enhanced after irradiation injury, which might be one of the compensatory mechanisms that promote the hematopoietic recovery after irradiation.

Protective Effects of Shikonin on Brain Injury Induced by Carbon Ion Beam Irradiation in Mice

Radiation encephalopathy is the main complication of cranial radiotherapy. It can cause necrosis of brain tissue and cognitive dysfunction. Our previous work had proved that a natural antioxidant shikonin possessed protective effect on cerebral ischemic injury. Here we investigated the effects of shikonin on carbon ion beam induced radiation brain injury in mice. Pretreatment with shikonin significantly increased the SOD and CAT activities and the ratio of GSH/GSSG in mouse brain tissues compared with irradiated group （P〈0.01）, while obviously reduced the MDA and PCO contents and the RO$ levels derived from of the brain mitochondria.

Study on the Effects of Guiqi Oral Liquid (归芪口服液) in Promoting Recovery of Hematopoiesis in AcuteIrradiation Injured Mice

Objective： To explore the effects and possible mechanisms of Guiqi Oral Liquid （归芪口服液, GQOL） on the recovery of hematopoiesis in acute irradiation injured mice. Methods： The acute irradiation injured mice were randomly divided into 2 groups： the treated group and the control group, and also a normal control group was set up with 6 mice in it receiving no treatment. After the mice in the former two groups were irradiated by 6.0 Gy ^60Coγ-ray, every one of them was given 0.4 ml GQOL or saline in equal volume through a gastric tube twice a day for 14 days. On the 4th, 8th and 14th day after irradiation, the bone marrow mononuclear cells （BMMNC） and megakaryocytes in bone marrow tissues of the mice were counted, the proportion of hematopoietic tissues （by area） was measured, and the expression of adhesion molecules, CD44 and CD54, in bone marrow were estimated by immunochemistry. The colony forming unit of spleen （CFU-S） in the mice were counted on the 8th day after irradiation. Results： On the 4th, 8th, 14th day after irradiation, the count of BMMNC and megakaryocyte, and the proportion of hematopoietic tissues in the treated group were higher than those in the control group （P〈0.01 or P〈0.05）. CD44 and CD54 expression in the treated group were higher than those in the control group on the 4th and 8th day （P〈0.01）, but near normal on the 14th day （P〈0.01）. On the 8th day, CFU-S count in the treated group was higher than that in the control group （P〈0.01）. Conclusion： GQOL can regulate the expression of adhesion molecules, CD44 and CD54, in the bone marrow of the acute irradiation injured mice, which may be one of the mechanisms of GQOL in accelerating the early phase hematopoiesis recovery of mice.

Dose-effect relationships in total body irradiation on the healing of cutaneous wounds

Objective To study the effects of dosages of total body irradiation on the healing process of cutaneous wounds and to observe the changes of wound area at different periods after injury.Methods The entire body irradiation from a 60Co γ-ray source was performed on Wistar rats. The single dosage varied from 1 to 8 Gy. Within 1 h after irradiation, two whole thickness circular cutaneous wounds corresponding to 2. 5% of total body surface area (φ =22 mm) were produced on the back of the animals (combined injury groups). Same wounds were produced on rats with no irradiation (single wound group). Wound healing was observed at different points after injury.Results After total body irradiation with the dose of 1,2,3,4,5,6, 7 or 8 Gy, the wound healing was obviously retarded as the dosages increased. The wound area remained was larger in the large dosage groups than in the small dosage groups. Seven days after injury, there was 33.5% wound surface left unhealed in the single wound group, whereas in the combined injury groups, 35.4%, 38.1 %, 41. 6%, 48. 8%, 53. 9%, 63. 7%, 69. 2% and 73. 9% of the wound surfaces remained unhealed, respectively. Statistical analysis showed marked correlations between the various times after total body irradiation and various dosages to the percentage of unhealed wound surface. Nine dose-effect relation formulae were deduced according to the statistical results.Conclusions In soft tissue trauma combined with radiation injury, the delay of wound healing is related to the dose of radiation inflicted. It is also related to the time between injury and time of observation.