Effects of bone marrow mesenchymal stem cells transplantation on the apoptosis of alveolar wall cells in papain and Co60-induced pulmonary emphysema rats / 中国应用生理学杂志

<p><b>AIM</b>To study the effects of bone marrow MSCs transplantation on the apoptosis of alveolar wall cells and the expression of Bcl-2 and Bax of lung tissue in papain and Co60-induced pulmonary emphysema rats.</p><p><b>METHODS</b>Female Lewis rats were randomly divided into three groups: control group, emphysema group, emphysema + MSCs transplantation group. Rats were sacrificed at days 14 and 28 after treatment. Morphologic analysis of the lung tissue was performed. The apoptosis of the lung cells was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. The expression of Bcl-2 and Bax were determined by immunohistochemical staining.</p><p><b>RESULTS</b>Emphysematous changes of the lung tissue were observed in emphysema group and emphysema + MSCs transplantation group. However, the emphysematous change in emphysema + MSCs transplantation group was improved compared with the emphysema group. There was significant difference in the number of alveolar counted per unit area (MAN), mean alveoli area (MAA) and mean linear interval(MLI) between emphysema group and emphysema + MSCs transplantation group. The apoptotic index of the alveolar wall cells in emphysema + MSCs transplantation group was less than that in the emphysema group. The percentage of Bcl-2 positive cells in emphysema + MSCs transplantation group was significantly higher than that in the emphysema group. The percentage of Bax positive cells in emphysema + MSCs transplantation group was significantly lower than that in the emphysema group. The ratio of Bcl-2/Bax of emphysema + MSCs transplantation group was significantly higher than that in the emphysema group.</p><p><b>CONCLUSION</b>Bone marrow MSCs transplantation inhibits the apoptosis of alveolar wall cells, upregulates the expression of Bcl-2 and downregulates the expression of Bax. This may be part of the reason that bone marrow MSCs transplantation improves the papain and Co60-induced pulmonary emphysema.</p>

Preoperative cobalt60 irradiation delays the healing of rectal anastomoses in rats

The healing of colorectal anastomoses after irradiation therapy continues to be a major concern. The authors evaluated the healing of rectal anastomoses in a rat model after a preoperative 500-cGy dose of cobalt60 irradiation. Thirty-six male Wistar rats were divided into two equal groups: control (group A), and irradiation group (group B). Group B received a single 500-cGy dose of irradiation, and a rectal resection and end-to-end anastomosis was performed in both groups on the 7th day after irradiation. Parameters of the healing process included bursting pressure and collagen content on the 5th, 7th, and 14th days after surgery. In the irradiation group, the mean bursting pressure on the 5th, 7th, and 14th days was 116, 218, and 273 mmHg, respectively. The collagen content assessed by histomorphometry was 9.0, 20.8, and 32 percent, respectively. In contrast, the control group had a mean bursting pressure of 175, 225 and 263 mmHg, and a collagen content of 17.8, 28.1, and 32.1 percent, respectively. The adverse effect of irradiation on healing was detectable only on the 5th postoperative day, as demonstrated by lower bursting pressure (P < 0.013) and collagen content (P < 0.008). However, there was no failure of anastomotic healing such as leakage or dehiscence due to irradiation. We conclude that a single preoperative 500-cGy dose of irradiation delays the healing of rectal anastomosis in rats.

Verification of radiation dose calculation for patients treated by Co-60 using 2-D planning system

In this study, experimental verifications is done for output, dose profile percentage depth dose for open and modified [wedged and partially blocked] fields as compared with the calculated using Multidata code. Four typical configurations of irradiation were selected, regular fields, wedged fields, blocked fields and cases of internal inhomogeneity. Measurements were performed on cobalt - 60 unit Theratron 780E using Multidata water phantom. For blocked fields dose profiles were measured using radiographic films and then scanned using PTW densitometer. Data were analyzed in both of the low and high dose gradient regions of the measured and calculated profiles. Differences between the measured and the calculated dose were determined. The results indicate that the Multidata planning system calculations agree with the measured ones in situations. However, in the blocked field the mean deviation between measured and calculated dose under the block was [15.2%] although the blocks is drown according to the instructions by the system manufactures. The reason for such errors was found to be due to the implemented algorithm in the system