Ultrastructure of focal cerebral cortex tissue from rats with focal cortical dysplasia

BACKGROUND： Developing a model of focal cortical dysplasia in microgyrus and observing the ultrastructure of focal tissue is of important significance for analyzing the pathology of cortical developmental disorder and the factors of structural changes. OBJECTIVE： This study was to observe the pathological characteristics of focal tissue around the microgyrus of rats with cortical developmental disorder using an electron microscope, so as to analyze the causes associated with cerebral cortical developmental disorder. DESIGN： A randomized controlled animal experiment. SETTING： The First Affiliated Hospital of Chongqing Medical University. MATERIALS： This study was carried out in the Chongqing Key Laboratory of Neurology, Room for Electron Microscope of Chongqing Medical University, and Laboratory Animal Center, Research Institute of Surgery, Daping Hospital, Third Military Medical University of Chinese PLA between January 2004 and August 2006. Eighteen healthy newborn male Wistar rats, weighing 3.0 - 6.0 g, provided by the Laboratory Animal Center, Daping Hospital, Third Military Medical University of Chinese PLA, were involved in this study. The protocol was carried out in accordance with animal ethics guidelines for the use and care of animals. Probes （Chongqing Wire ＆ Cable Factory, China） were made of copper core wire with diameter of 1mm. METHODS： The rats were randomly divided into 3 groups with 6 in each： normal control group, liquid nitrogen injured group and sham-operation group. （1）In the liquid nitrogen injured group, a blunt probe frozen by liquid nitrogen was placed on fronto-parietal crinial bone of rats for 8 s. A 3 - 5 cm of microgyrus was induced in the unilateral cerebral sensory cortical area. In the sham-operation group, probe was placed at the room temperature. In the normal control group, rats were untouched. （2） The conscious state and electrical activity of brain of rats in each group were observed. （3） 2 - 3 mm thickness of hippocampal tissue with coronary section was taken for observing its ultrastructure under a transmission electron microscope. MAIN OUTCOME MEASURES： （1） The ultrastructure of hippocampal tissue. （2）The conscious state and electrical activity of brain of rats. RESULTS： Eighteen rats were enrolled in the final analysis. （1） Observation of hippocampal ultrastructure： Electromicroscopic pathological findings showed that for each rat of the liquid nitrogen injured group, mitochondrium in the pyramidal neuron around the microgyrus was swelled, endoplasmic reticulum was expanded, glial cells were swelled, water gathered around the blood capillary, partial medullary sheath was degenerated, neuropilem was normal and no obviously abnormal synapse was found. （2） Changes in conscious state of rats： Rats in the normal control group and sham-operation group had no convulsive seizure, but those in the liquid nitrogen injured group had occasionally. Most of them showed increased activities, excitation and restlessness, scratching and frequent ＂ watching face-like activities＂. （3）Electrical activity of brain of rats： Electroencephalogram recording of liquid nitrogen injured group showed that small wave amplitude of rhythm took the main part. No typical sharp wave, V wave, sharp and slow wave, V and slow waves were discharged. CONCLUSION： Liquid nitrogen can lead to cerebral cortical developmental disorder. Pathological changes of ultrastructure of focal tissue around the microgyrus can provide pathological basis for epilepsy associated with focal cortical developmental disorder.

The Effect of Bioceramic Composite Extracellular Matrixes Used to Repair Bone Deficiency on Relevant Blood Biochemical Indices

At the base of experimental animal model construction of bone defect in New Zealand rabbit, the promoting repair effect of bioactive ceramics on bone defect as well as its machanism was studied through testing body mineral elements, enzymes related to bone morphogenetic proteins and some biochemical indexes. Refering to some documents, materials of TCP, CHA and HA were combined and TCP/BMP/ TCP-β1 and CHA/BMP/ TCP-β1,HA/BMP/ TCP-β1 composite materials were made. All kinds of them were implanted into the radial defect site of rabbit, respectively. The chosen blood indexes (Ca, P, ALP, GGT, AST, ALT, TPA, BUN and Cr) were tested by colorimetry, speed rate and bromocresol green testing methods. No abnormal effects were found in any animal after operation. Serum concentrations of Ca, P and ALP were increased with the length of time in all groups of the three kinds of composite material, mixed material and pure materials. The increases in composite material groups were more significant (P<0.05). Comparison of the three kinds of material showed TCP>CHA>HA. There was a tendency of increased TPA and decreased BUN with the length of time. There was no significant difference between the composite material groups and pure material group (P>0.05). The three kinds of bioactive ceramics composed of extracellular matrix could increase the serum concentrations of Ca and P and activity of ALP after being implanted into defect bone and showed some repairing capacity. This provided a new area of machanism study of bone defect repair by biomaterials.

端粒酶核酶时间治疗肝癌裸鼠移植瘤研究(英文)

目的探讨在端粒酶峰值时相与谷值时相施以端粒酶抑制剂治疗肝癌裸鼠移植瘤的疗效差异。方法24只BALB/C裸鼠进行为期4wk的LD12∶12节律同步化。移植肝癌细胞(SMMC-7721)于裸鼠以建立肝癌裸鼠移植瘤。在移植后2wk,瘤体内注射端粒酶抑制剂hTERT-5’RZ以治疗肝癌裸鼠移植瘤,注射时间点为9HALO或21HALO,持续2wk。结果21HALO治疗组的肿瘤抑制率(65%)和端粒酶抑制率(90%)高于9HALO治疗组的肿瘤抑制率(48%)和端粒酶抑制率(70%),差异具有统计学意义。结论在肿瘤DNA合成期注射以端粒酶为作用靶点的核酶能更好地抑制肝癌生长,具有更好的治疗效果。