[The effect of continuous low doses X-ray on the proliferation of pyramidal cell in hippocampus CA1 in prenatal rats].

OBJECTIVE: To explore the effect of low doses X-ray on proliferation of hippocampal pyramidal cell in the area of CA1 in prenatal rat and its relevant mechanism. METHODS: A total of 25 pregnant rats were randomly divided into four experimental groups and one control group. The experimental groups, in a duration of consistent 18 days, respectively received different doses as follows: 0.015 mGy/d, 0.03 mGy/d, 0.06 mGy/d and 0.09 mGy/d. The control group received sham radiation. To observe the density and width of hippocampal pyramidal cell in the area of CA1 by HE stained and observe the expression of the ERK1/2 by IHM. RESULTS: (1) Except C group, all other groups presented increment in width of the level of hippocampal pyramidal cell, compared with C group; H group, M group, L1 group and L2 group were higher than that (F value respectively were 8.475, 33.42, 14.395, 44.955; P value respectively were 0.002, 0.048, 0.030, 0.012). But the phenomenon of inhomogeneity in width in H group was observed, at the same time, the density of cell in H group became looser (F = 4.466, P = 0.017). (2) The expression of ERK1/2 in the hippocampus CA1 was seen in cytoplasm of every group, the average optical density of positive ERK1/2 protein significantly increased in L1 group and L2 group, compared with control group respectively (F value respectively were 4.561, 4.103, P value respectively were 0.044, 0.035). CONCLUSION: Low doses X-ray could promote proliferation of hippocampus CA1 cell in prenatal. The reason could be the increment of the ERK1/2 protein induced by X-ray. When the doses reached 0.09 mGy/d, the excesses proliferation phenomenon was observed.

[CT and pathological manifestations of intraductal papillary mucinous neoplasm of pancreas: a comparative study].

OBJECTIVE: To evaluate the diagnostic value of CT in pancreas intraductal papillary mucinous neoplasm (IPMN) by analyzing its CT feature and pathological findings. METHODS: The clinical and CT data was analyzed among 39 patients with IPMN whose diagnosis was confirmed by pathology. The CT manifestations were classified into 3 types: simple main pancreatic duct enlargement; main pancreatic duct enlargement combined with pancreatic cystic lesion; and simple pancreatic cystic lesion. The correlation between the CT types and Takada pathological types (main duct type, branch type, and mixed type) was analyzed. All the cases were pathologically classified into benign and malignant/boundary groups. Statistical tests of the difference of CT features (mural nodule, septa, size, caliber of main pancreatic duct and common bile duct) between the 2 groups were performed. RESULTS: The CT type I matched the main duct type, the CT type II mainly matched the branch type and mixed type, and the CT type III matched the branch type (P < 0.001). The probability of benign lesion was 92% with no mural nodule in the lesion, while the probability of benign lesion was only 42% with mural nodule presented (P = 0.003). In terms of the septa, there was no significant difference between benign and malignant lesions (P = 0.793). The size of malignant/boundary lesions exceeded that of benign lesions (P = 0.016). There were no significant difference in calibers of main pancreatic duct and common bile duct between the benign and malignant/ boundary groups. Without considering pathological grouping the caliber of main pancreatic duct exceeded that of the common bile duct in all the cases (P = 0.02). CONCLUSION: CT typing of IPMN well matches the pathological typing which benefits the CT diagnosis of IPMN. The caliber of main pancreatic duct usually exceeds that of common bile duct in IPMN. This feature contributes to its diagnosis.