ABSTRACT
<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>(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).</p><p><b>CONCLUSION</b>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.</p>
Subject(s)
Animals , Female , Male , Pregnancy , Rats , Cell Proliferation , Radiation Effects , Hippocampus , Cell Biology , Radiation Effects , Maternal Exposure , Neurons , Cell Biology , Radiation Effects , Pyramidal Cells , Cell Biology , Radiation Effects , Radiation, Ionizing , X-RaysABSTRACT
Objective We used blood oxygenation level dependent-functional MR imaging(BOLD- fMRI)to explore the characteristics of deactivation patterns in patients with anxiety disorders and the underlying neural mechanism of this disease.Methods Ten patients and ten healthy controls participated the experiments.All subjects performed the trait portion of the State-Trait anxiety Inventory(STAI-T)prior to the fMRI scans.The subjects underwent noninvasive functional magnetic resonance imaging while listening actively to emotionally neutral words alternating with no words(experiment 1)and threat related-words alternating with emotionally neutral words(experiment2).During fMRI scanning,subjects were instructed to closely listen to each stimuli word and to silently make a judgment of the word's valence.Data were analyzed with statistical parametric mapping(SPM 99).Individual and group analysis were conducted.Results Mean STAI-T score was significantly higher for patients group than that of controls(58?8 for patients group and 33?5 for controls,t=8.3,P
ABSTRACT
Objective To analyze and compare the MRI appearances of ovarian thecoma with pathologic findings in order to improve the knowledge of the disease.Methods Nineteen cases of ovarian thecoma confirmed by histopathology were analyzed.MRI morphological characteristics and signal intensity of the lesions were observed and compared with findings of pathomorphology.Correlation analysis between tumor size and amount of ascites was made.Results Ovarian thecoma displayed iso-or hypointense signal on T_1WI and significant hypointensity in the focal lesion on T_2WI.Hyperintensity occurred when cystic degeneration of the lesions existed.Fibrous septation was detected in some lesions.After enhancement,most lesions showed mild early enhancement with slight increase on the delayed phase.Pathological necrosis and cystic degeneration were seen in 9 cases which corresponded to the number and shape of the cystic lesions on MRI.A large amount of collagen hyperplastic was found between the oncocytes microscopically in 15 cases, which displayed significant hypointensity in the focal lesion on T_2WI;another 4 cases showed relatively less amounts of collagen hyperplastic and more oncocytes,which appeared moderate intensity in the focal leisom on T_2WI.The amount of ascites was not significantly correlated with the lesion size(r=0.43,P=0.10). Conclusions Hypointensity on T_2WI and mild enhancement pattern due to poor blood supply are the characteristics of ovarian thecoma.The MR findings can reflect the pathologic features of the tumor,which is helpful in the diagnosis and differential diagnosis.