Objective To investigate the expression pattern of hypoxia-inducible factor 1α (HIF-1α) in experimental secondary spinal cord injury (SSCI) in rats and its potential effects on SSCI. Methods A total of 66 SD rats (female or male) with weight (250 ± 20) g were randomly divided into 3 groups: normal control group (group A, n=6), pseudo injury group (group B, n=6), and spinal cord injury (SCI) group (group C, n=54). In group A, no treatment was given as normal control. In groupB, only laminectomy was appl ied. In group C, laminectomy was appl ied and static compression model of SCI was built at T10 level. The expression of HIF-1α was measured with HE and immunohistochemical staining in groups A, B (1 hour after pseudo injury), and C (1, 3, 6, 12 hours and 1, 2, 3, 7, 14 days after SCI). Results All rats survived to the end of the experiment. HE staining showed that the spinal tissue of groups A and B were dense and the nucleus were round and big with l ight staining and clear nucleolus. The injured neuron at 1-12 hours after SCI of group C presented pyknosis and deep eosin staining. The swelling axon with bubbles and the disintegrated and disorganized medullary sheath in white matter appeared at 1-3 days after SCI. The hyperplasia of gl ial cells were obvious and gray matter cells were broken and apoptosis with cavities in injured spinal segment was observed at 7 and 14 days after SCI. Immunohistochemical staining showed that HIF-1α was poorly expressed in group A and increased a l ittle in group B. The positive expression in group C increased at 3 hours after SCI, which was found in spinal cord anterior horn neurons and a small amount of gangl ion cells. It reached peak at 1 day, maintained at a high level during 1-3 days and then decl ined. At 14 days, it appeared only in a small amount of gangl ion cells of white matter. There was no significant difference in the number of HIF-1α positive cells between groups A and B (t=1.325, P=0.137). The number of HIF-1α positive cells at each time point in group C was more than those in groups A and B (P lt; 0.05), and there were significant differences between all time points in group C (P lt; 0.05). Conclusion The expression of HIF-1α increases after SCI, it is related to the ischemia hypoxia after SSCI, and the expression pattern was correlated with the injury time.
Objective To analyze the risk factors inducing tumor cells exfoliating during radical resection of rectal cancer. Methods Sixty patients who were diagnosed as rectal cancer from May 2006 to November 2007 and given radical operations were assigned prospectively in this study. Before cutting the rectal stump below the tumor, saline was instilled into rectum to irrigate the stump. Collected irrigating fluids were sent to pathology laboratory, and the exfoliated malignant cells were tested by HE （haematoxylin and eosin） dyeing and common smear technique. The results of examines were collected and statistical analysis, including a Logistic regression model, was performed. Results Exfoliated malignant cells were found in 27 samples. By univariate analysis, the statistically significant factors defining a high risk of exfoliating were age, tumor size, TNM stage, operation time and operation method (Plt;0.05). Only TNM stage， operation time and operation method were confirmed by Logistic regression analysis to independently result in a statistically significant increased risk of exfoliating. Conclusion Irrigating the rectal stump before cutting down the tumor is essential to avoid local recurrence. The effects of TNM stage, tumor size and operation time are important. Although the laparoscopic surgery is more predominant than conventional surgery for non-neoplasma technology, irrigating is an important process.