Protective function of nimodipine on facial nerve injury and its effect on expression of glial cell line-derived neurotrophic factor / 中华神经医学杂志

Objective To study the protective function of nimodipine on facial nerve injury and its effect on the expression of glial cell line-derived neurotrophic factor (GDNF). Methods Ninety-six SD rats were randomly divided into sham-operated group, facial nerve injury group, nimodipine pretreatment group, and nimodipine post-treatment group. Rat models of facial nerve injury in thc later 3groups were established. The dynamic changes of expression of GDNF were observed by HE staining and Western blotting in different treatment groups and at different time points (1, 3 and 6 months after the injury). Restdts Compared with the facial nerve injury group, the nimodipine pretreatment and post-treatment groups had significantly less severe nerve damage and significantly up-rcgulated expression of GDNF (P＜0.05). The expression of GDNF in the nimodipine pretreatment group was statistically higher than that in the nimodipine post-treatment group (P＜0.05). However, the expression of GDNF in the nimodipine post-treatment group was not statistically different from that in the facial nerve injury group 3 and 6 months after the injury (P＞0.05). Conclusion Nimodipine has significant facial nerve protective effect, and one of the mechanisms of nimodipine to protect the facial nerve is to regulate the GDNF expression.

Optimization of primary culture of neural stem cells / 中华神经医学杂志

Objective To study the influence of digestion times of low concentration trypsin on the proliferation and apoptosis of neural stem cells (NSCs) in the hippocampus of neonate rats.Methods Hippocampus of neonatal rats (within 24 h) were taken out, and treated with trypsin at 1.25g/L concentration and 37 ℃ for 5, 10, 15, 20 and 25 minutes; unicellular suspension was then successfully got and primary culture and subculture were performed. Effects of trypsinization on cell viability and growth of NSCs were compared by observing the cell morphology and Trypan blue staining.The 5-bromodeoxyuridine labeling was performed to assess the self-renewing and proliferative activities of NSCs. Fluorescence immunocytochemistry was carried out to examine the expressions of BrdU and nestin. Apoptosis was measured by Annexin V-FITC/PI assay and flow cytometry. Results Primary and passage culture of NSCs enjoyed rapid proliferation and formation of neurospheres. The neurosphere cells expressed NSCs specific marker nestin by immunofluorescence; all the neurosphere cells could incorporate BrdU into the nucleus; of the neurospheres obtained from the 3rd, 5th and 7th d, those digested for 15 rain enjoyed the highest level of NSCs neurospheres, the highest BrdU labeled clone and the lowest cell apoptosis as compared with those digested for 5, 10, 20 and 25 min (P<0.05). Conclusion The NSCs isolated from the hippocampus of neonatal rats have the ability of proliferation in vitro. And 1.25 g/L concentration of trypsin with digestion times could positively change the proliferative and apoptosis capacity of NSCs: too short or long digestion times can inhibit the proliferation of NSCs and induce the apoptosis of NSCs; the longer the digestion time, the higher the apoptosis of NSCs.

Effect of imatinib at different concentrations on rat C6 glioma cell apoptosis and cell cycle / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of imatinib on rat C6 glioma cell apoptosis and cell cycle.</p><p><b>METHODS</b>MTT assay was used to determine the OD value of C6 glioma cells following treatment with imatinib at different concentrations (0.156, 10 and 15 micromo/L) for 24, 48 and 72 h. The cell apoptosis was assayed by Hochest/PI staining and the cell cycle changes were analyzed by flow cytometry.</p><p><b>RESULTS</b>Imatinib treatment resulted in increased number of apoptotic cells in a time- and dose-dependent manner. A 72-h treatment of the cells with imatinib at 10 and 15 micromo/L caused increased cell percentage in G(0)/G(1) phase to (68.53-/+0.83)% and (70.41-/+0.62)%, (P<0.01), decreased the percentage of G(2) phase cells to (14.48-/+0.12)% and (13.84-/+2.86)% (P<0.01), and decreased the percentage of S phase cells to (16.98-/+0.72)% and (15.78-/+2.28)%, respectively (P<0.01).</p><p><b>CONCLUSION</b>Imatinib can induce apoptosis and affect the distribution of the cell cycle of C6 cells in vitro.</p>

Expression of cathepsin D in the central, peripheral and edematous areas of human astrocytomas / 中华神经医学杂志

Objective To study the expression of cathepsin D (CathD) in the central, peripheral and edematous areas of human astrocytomas and its clinical implications. Methods Forty-one patients with astrocytomas showing clear boundaries between the tumor area and the edematous area but without tumor necrosis or cystic degeneration as shown by magnetic resonance imaging (MRI) were divided into recurrent group (13 patients) and non-recurrent group (28 patients). Surgical specimens of the tissues in the central, peripheral and edematous areas of the tumor were obtained according to MR images using FLAIR sequence for detecting CathD expression with immunohistochemistry Results Normal brain tissues had virtually no or low CathD expression. Positive CathD expression was found in the central, peripheral and edematous areas of the astrocytomas, and the expression was significantly higher in the peripheral area (2.610±0.945) than in the central area (10.780±1.557) of the tumor (P<0.05). Patients in the recurrent group had more intense CathD expression in the peripheral area of the tumor than those in the non-recurrent group (11.539±1.127 vs 10.429±1.620, P<0.05), but in the central area of the tumor, the expression was comparable between the two groups (P>0.05). Conclusion Obvious CathD expression in the peripheral and edematous areas of the astrocytomas may suggest the likeliness of potential astrocytoma infiltration in these areas. The relative low CathD expression of CathD in the central area of the tumor indicates almost total degradation of the extracellular matrix as a result of early tumor invasion. CathD expression in the peripheral and edematous areas of the astrocytomas may serve as an indicator of tumor recurrence.

Expression and localization of α7-nicotinic acetylcholine receptors on rat hippocampal microglial cells / 中华神经医学杂志

Objective To investigate the expression and distribution of α7-nicotinic acetylcholine receptors (α7-nAChR) on rat hippocampal microglial cells. Mehtods Mixed primary glial cells obtained from the cerebral cortex of 1-day-old rats were cultured for 7-9 days, and the microglial cells were purified. The expression of α7-nAChR at the protein and mRNA levels on the microglia cells was detected using double immunolabeling with anti-CD11b/c antibody and RT-PCR. respectively. Results The resting microglial cells harvested from mixed primary glial culture presented with ramified surface covered with spines, which may serve as a unique feature for identifying microglial cells. A band of 450-bp corresponding to α7-nAChR was specifically amplified by RT-PCR.Double immunolabeling showed colocalization of α7-nAChR and CD11b/c on the cultured hippocampal mcrioglial cells. Conclusion α7-nAChR can be normally expressed in rat hippocampal microgiial cells in in vitro culture.

Histomorphology of angiogenesis patterns in different areas of human astrocytomas / 南方医科大学学报

<p><b>OBJECTIVE</b>To study angiogenesis patterns in the edematous area and the center of human astrocytomas by histological observation, and to reveal histological basis of vasculogenic mimicry.</p><p><b>METHOD</b>Tissue samples were drawn from the tumor center and the edematous area in 51 patients with human astrocytomas during operation MR and were examined by CD34 endothelial marker periodic acid-Schiff (PAS) dual staining.</p><p><b>RESULTS</b>Vessels or capillaries stained by both PAS and CD34 were found in edematous areas of human astrocytomas. Besides vessels or capillaries stained by both PAS and CD34, vasculogenic mimicries (PAS-positive and CD34-negative tubes containing red blood cells and lined by neoplastic cells), PAS-positive and CD34-negative tubes containing red blood cells and without cells around, PAS-positive and partial CD34-positive vessels or capillaries, and PAS-positive and CD34-negtive vessels or capillaries were detected in the center of tumor of 4 human glioblastomas.</p><p><b>CONCLUSIONS</b>Vasculogenic mimicries in the center of some high-grade astrocytomas may be caused by blood capillary dysplasia, while angiogenesis patterns are vessels or capillaries in the edematus area and the center of most human astrocytomas.</p>

Proton magnetic resonance spectroscopic imaging of the hippocampus in schizophrenia patients before and after surgery / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the features of proton magnetic resonance spectroscopy (1H-MRS) of the hippocampus in schizophrenia patients before and after stereotactic neurosurgery.</p><p><b>METHODS</b>1H-MRS was performed to determine NAA/Cr and CHO/Cr ratios on the bilateral hippocampal regions before and after stereotactic neurosurgery in 20 schizophrenia patients, with 20 healthy individuals as the controls.</p><p><b>RESULTS</b>The NAA/Cr ratio in the hippocampal regions was significantly lower and the CHO/Cr ratio significantly higher in schizophrenia patients before the surgery than in the healthy controls (P<0.01). The NAA/Cr and CHO/Cr ratios in the hippocampal regions underwent no significant changes in the patients after the surgeries (P>0.05).</p><p><b>CONCLUSION</b>Neuronal and cell membrane metabolism impairment is present in the hippocampus of schizophrenia patients, and stereotactic neurosurgery does not produce obvious adverse effects on the cell membrane metabolism in the hippocampus of the patients.</p>

Effects of fluoxetine and amitriptyline on rat behaviors in forced swimming test and phosphorylated ERK1/2 level in rat brain / 中华神经医学杂志

Objective To investigate the effects of fluoxctine and amitriptyline on rat behaviors in the forced swimming test(FST)and phosphoryhted ERK1/2 level in the rat brain.Methods Thirty male SD rats were randomly divided into three groups(n=10):ftuoxefine(FLX),amitriptyline(AMT) and control(CON) groups.Treated groups were injected with 20 mg/kg fluoxetine and 20 mg/kgamitriptyline,respectively,23 h after the 15-rain pie-test of FST.The animals in CON group were injected with the same volume of distilled water.Thell a 5-min FST was conducted 1 h later.The 5-min test sessions were videotaped and the time span for each behavior(latency of immobility.immobility,swimming and climbing)was recorded.All rats were sacrificed with a perfusion of 4% paraformaldehyde immediately after the termination of the test.Immunohistochernical ABC staining was used to observe the distribution of pERK1/2-like immunoreactive(LI)neurons in the brain. Results(1)The latency of immobility in AMT group was significantly longer than that of CON group during the 5 min FST (P<0.05),and the climbing time in AMT group was longer than that of CON group and FLX group(P<0.05),while the duration of immobility in AMT group was obviously shorter in comparison with CON group (P<0.05).The duration of swimming behavior in FLX group was longer than that of CON group as well as AMT group(p<0.05).(2)Numbers of pERK1/2-LIneurons in FLX group were greatly reduced in prefrontal codex(PFC),cingulate gyms(Cg)and prelimbic cortex(Prl) in comparison with that of CON and AMT group(P<0.05),while the expressed pERK1/2 in AMT group was significantly decreased in the neurons of ventrolateral septum(LSV)in comparison with that of CON group(P<0.05).And compared with CON group,the numbers of pERKl/2-LI neurons in both drug treated groups were greatly reduced in hypothalamic paraventricular nucleus (PVN) and more significantly in AMT group(P<0.01).Conclusion Administration of fluoxetine and amitriptyline have different effects on rat behaviorals in the FST.Both of them may be have some effects on anti-negative psychological stress.The ERKI/2 pathway possibly plays a role in this process.