A simple method for assessment of RNA integrity in laser capture microdissection samples / 南方医科大学学报

<p><b>OBJECTIVE</b>To develop a simple method for assessment of RNA integrity in laser capture microdissection (LCM) samples.</p><p><b>METHODS</b>The total RNA were isolated from the LCM samples and the sections before and after microdissection and examined by agarose gel electrophoresis. Real-time PCR was employed to assess the RNA from LCM samples, and the quantity of RNA was theoretically estimated according to the average total RNA product in mammalian cells (10 ng/1000 cells).</p><p><b>RESULTS</b>When the total RNA from the sections before and after microdissection was intact, the RNA from LCM samples also had good quality, and the 28S and 18S rRNAs were visualized by ethidium bromide staining. Real-time PCR also showed good RNA quality in the LCM samples.</p><p><b>CONCLUSION</b>A simple method for quantitative and qualitative assessment of the RNA from LCM samples is established, which can also be applied to assessment of DNA or proteins in LCM samples.</p>

Effects of ligustrazine on hippocampal dentate gyrus cell proliferation after focal cerebral ischemia in adult rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effects of ligustrazine on cell proliferation in hippocampal dentate gyrus subgranular zone (SGZ) after focal cerebral ischemia in adult rats.</p><p><b>METHODS</b>Middle cerebral artery occlusion (MCAO) model was established in adult rats by placement of an intraluminal filament at the origin of the MCA. Ligustrazine was administered intraperitoneally at a daily dose of 80 mg/kg starting at 2 h after MCAO, and BrdU (50 mg/kg daily) was also injected intraperitoneally starting at 4 h after MCAO. BrdU-positive cells in the SGZ were counted 7, 14 and 24 days after MCAO, respectively.</p><p><b>RESULTS</b>Compared with sham operation group, ischemic ipsilateral BrdU-positive cells in the ischemic model group increased 7 days after MCAO, reaching the peak on day 14, and decreased on day 21 (P<0.01). The number of ischemic ipsilateral BrdU-positive cells in ligustrazine group was significantly greater than that in the ischemic model group on days 7, 14 and 21 (P<0.01), and maintained the high level on day 21.</p><p><b>CONCLUSION</b>Ligustrazine possesses long lasting effect of promoting cell proliferation in the SGZ after focal cerebral ischemia in adult rats.</p>

Effects of ketamine-midazolam anesthesia on the expression of NMDA and AMPA receptor subunit in the peri-infarction of rat brain / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Activation of N-methyl-D-aspartate (NMDA) receptors and alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors play an important role in the neurons death induced by ischemia. The mitigating effect of intravenous anesthetics on ischemic neuron injury is related to their influence on NMDA receptors. This study was performed to investigate the effect of ketamine-midazolam anesthesia on the NMDA and AMPA receptor subunits expression in the peri-infarction of ischemic rat brain and explore its potential mechanism of neuroprotection.</p><p><b>METHODS</b>Thirty Sprague Dawley (SD) rats were subjected to permanent middle cerebral artery occlusion under ketamine/atropine (100/0.05 mg/kg) or ketamine-midazolam/atropine (60/50/0.05 mg/kg) intraperitoneal anesthesia (n=15 each). Twenty-four hours after ischemia, five rats in each group were killed by injecting the above dosage of ketamine or ketamine-midazolam intraperitoneally and infarct size was measured. Twenty-four and 72 hours after ischemia, four rats in each group were killed by injecting the above dosage of ketamine or ketamine-midazolam intraperitoneally. After staining the brain tissue slices with toluidine blue, the survived neurons in the peri-infarction were observed. Also, the expression level of NMDA receptors 1 (NR1), NMDA receptors 2A (NR2A), NMDA receptors 2B (NR2B) and AMPA (GluR1 subunit) were determined by grayscale analysis in immunohistochemical stained slices.</p><p><b>RESULTS</b>Compared with ketamine anesthesia, ketamine-midazolam anesthesia produced not only smaller infarct size [(24.1+/-4.6)% vs (38.4+/-4.2)%, P<0.05], but also higher neuron density (24 hours: 846+/-16 vs 756+/-24, P<0.05; 72 hours: 882+/-22 vs 785+/-18, P<0.05) and lower NR2A (24 hours: 123.0+/-4.9 vs 95.0+/-2.5, P<0.05; 72 hours: 77.8+/-4.1 vs 54.2+/-3.9, P<0.05) and NR2B (24 hours: 98.5+/-2.7 vs 76.3+/-2.4, P<0.05; 72 hours: 67.2 +/-7.5 vs 22.2+/-2.6, P<0.05) expression level in the peri-infarction following ischemia.</p><p><b>CONCLUSION</b>The protective effects of ketamine-midazolam anesthesia on ischemic brain injury may related to decreasing NR2A and NR2B expression.</p>

Effect of histamine on intracortical blood vessels of rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate histamine-induced changes of the intracortical vessels in the cortical slice of rat brain.</p><p><b>METHODS</b>Immunohistochemistry was employed to detect the expression of H1 and H2 receptors in the intracortical blood vessels of rats. Histamine-induced constriction of the intracortical blood vessels of the brain slices was observed with differential interference contrast microscope. Measurements of the luminal diameter were made on-line during the course of the experiment and confirmed off-line from the stored images. In order to observe whether histamine H1 and H2 receptors affected histamine-induced constriction, the intracortical blood vessels in the brain slices were pre-treated with H1 receptor antagonist diphenhydramine and H2 receptor antagonist cimetidine.</p><p><b>RESULTS</b>Expression of H1 and H2 receptors was detected in the intracortical blood vessels of the rat brain. Histamine (1-100 micromol/L) induced a concentration-dependent constriction from (1.48-/+0.67)% to (32.91-/+7.91)%. The reactions to each histamine concentration were significantly (P<0.01) different from each other, with the exception of the highest histamine concentrations (30 and 100 micromol/L) when maximal constriction due to histamine were observed (P>0.05). With pre-treatment of the slice with 10 micromol/L diphenhydramine, application of histamine did not elicit constriction. Pre-treatment of the slice with 10 micromol/L cimetidine did not completely inhibit but somehow significantly weakened vascular constriction in response to histamine treatment at 10 and 30 micromol/L (P<0.05).</p><p><b>CONCLUSION</b>Histamine can induce constriction of the intracortical blood vessels, which is mediated by H1 receptor.</p>

Effect of citicoline on spatial learning and memory of rats after focal cerebral ischemia / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of citicoline on spatial learning and memory of rats after focal cerebral ischemia.</p><p><b>METHODS</b>The rats were randomly divided into sham-operation group, ischemia control group and citicoline group. In the later two groups, focal cerebral ischemia model was established by introducing an intraluminal filament into the left middle cerebral artery, and citicoline (500 mg/kg) or 0.9% NaCl was administered intraperitoneally once a day for 2 weeks after the operation. The rats in the sham-operation group were not subjected to middle cerebral artery occlusion (MCAO) with intraluminal filament. The spatial learning and memory functions of the rats were evaluated by Morris water maze test 15 days after MCAO for 5 days.</p><p><b>RESULTS</b>The rats in ischemia control group exhibited serious spatial learning and memory deficits in both place navigation test and spatial probe test. In the former test, the mean escape latency of citicoline-treated rats were significantly shorter than that of ischemia control rats (P<0.01), and in the latter test significant diffidence was noted between citicoline and ischemia control groups in the percentage time spent in the former platform quadrant and frequency of crossing the former platform (P<0.05).</p><p><b>CONCLUSION</b>Citicoline can improve the spatial learning and memory function of rats after focal cerebral ischemia.</p>

Genetic polymorphism of 9 STR loci in Han nation population in Shandong Province / 中国医学科学院学报

<p><b>OBJECTIVE</b>To study genetic polymorphism of 9 STR loci in Han nation population in Shangdong Province.</p><p><b>METHODS</b>We investigated 100 unrelated individuals of Han nation population in Shandong Province and studied their genetic distribution of 9 STR loci and Amelogenin locus. Primers of 10 loci were labeled with the NHS-ester fluorescent dye 5-FAM (blue), Joe (green) or NED (yellow). The data of Han nation population were generated by multiple amplification and subjected to GeneScan, genotype and genetic distribution analysis.</p><p><b>RESULTS</b>83 alleles and 220 genotypes were observed, with the corresponding frequency of 0.0050-0.4050 and 0.0100-0.2100. The average of heterozygosity was 0.7778, the accumulated discrimination power was 0.9999. The accumulated probability of exclusion paternity was 0.9999. The polymorphism information content was 0.5823-0.8396.</p><p><b>CONCLUSIONS</b>Chi-Square test indicated that the distribution of genotypes agreed with Hardy-Weinberg equilibrium.</p>