ABSTRACT
Objective To establish a serum-free primary culture method for cortical neurons of new-born rats .Methods The cortical tissue was digested and the cells were planted in the medium containing 10% fetal bovine serum ,and then maintained feed-ing with neurobasal medium containing B27 after 4 to 8 h .The morphology was observed under phase-contrast microscope .RT-PCR ,Western blot and immunocytochemistry were applied to identify the expression of NSE gene and protein in neurons .Results A large number of neurons began to adhere to the cover glasses after 2 to 8 h .They showed different shapes-shuttle ,triangle pyram-idal ,or no regular after clinging to the plate .Their processes connected to nets and were different in length and thickness .They well developed at the 7th to 10th day .The isolated and cultured cells were confirmed as neurons by RT-PCR ,Western blot and immuno-cytochemistry .Conclusion This technique is an easy and practical tool for primary culture of new-born rats cortical neurons with high purity ,and can be used as an in-vitro model of research .
ABSTRACT
Objective To detect time-dependent change of neuritin expression in brain tissues after traumatic brain injury and discuss the effect of neuritin after brain damage occurred. Methods Forty-two rats were divided into normal group, control and experimental group. According to the postoperative time divided into 6 subgroups, including 6 hours group, 12 hours group, 24 hours group, 3 days group, 7 days group and 14 days group. Immunohistochemical and western-blot were used to detected the protein expression levels of neuritin. Results The immunohistochemical staining indicated that the positive expression of neuritin was strong in the cytomembrane and cytoplasms of the neurons, with a higher intensity, 6 hours after the operation. 12 hours after the operation last to the seventh day, the neurons with the strongest positive expression, is significantly higher than control group and normal group, significant decrease on the fourteenth day. The result of western-blot indicated that the level of neuritin protein sharply increased at 6 hours, reached the peak on 24 hours and after lasted to the seventh day, significantly higher than control group and normal group (P < 0.01), significant decrease on the fourteenth day (P < 0.05). Conclusion Up-regulation of neuritin in cerebral contusion tissues may play an important role after traumatic brain injury.
ABSTRACT
Objective To study hematotoxic effect of formaldehyde in mice.Methods Sixty healthy KM mice were randomly divided into a control group and three formaldehyde treated groups named a low level group,a moderate level group and high level group.Themice in the experimental groups were exposed to formaldehyde by intraperitoneal injection,once a day,for three weeks at the dose of 0.2,2.0 and 20 mg/kg bw respectively.Five mice were sacrificed at the 1st,2nd,3rd week of formaldehyde treatment and the blood samples were collected.The red blood cell counts,white blood cell counts and the hemoglobin content in the blood in mice were determined.Results During the experimental period,the body weight of mice in low level group at the 1st and 3rd week decreased significantly compared with the control group.The organ coefficient of the kidney in the moderate level group,high level group at the 1st week were higher than that of control group.The organ coefficient of the spleen in moderate level group at the 2nd week,in all three formaldehyde treated groups at the 3rd week was lower than that of control group.The organ coefficient of the heart in high level group at the 3rd week also decreased markedly in comparison to that of control group.The hemoglobin content in high level group at the 3rd week was lower than that of the control group.The red blood cell counts in three experiment groups at the 1st week and in high level group at the 2nd week decreased markedly compared with the control group.The white blood cell counts were seen much lower in low level group at the first two weeks,in moderate level group at the 1st week and in high level group in the experimental period compared with the control group.Conclusion Formaldehyde exposure has some hematotoxic effects in mice.