Comparison of two contrast agents for diagnosis of patent foramen ovale by contrast transcranial Doppler / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare agitated saline solution (AS) and the mixture of AS with blood (ASb) as the contrast agents in contrast transcranial Doppler (c-TCD) in the diagnosis of patent foramen ovale (PFO).</p><p><b>METHODS</b>We recruited 248 consecutive patients for c-TCD examination between November 2015 and January 2016, and the sequence of the use of AS (9 mL saline solution mixed with 1 mL air) and ASb (9 mL saline solution and a drop of the patient's blood mixed with 1 mL air) was determined by coin-tossing method. Before the examination, the contrast agent was injected with or without Valsalva maneuvers (VM), and the number of microbubbles within 25 s after the contrast agent injection and the time of first appearance of microbubbles were recorded by observing the TCD spectrum. Each injection was repeated twice and the interval between tests was at least 5 min. We classified PFO according to the number of microbubbles into negative (no microbubble), grade I (1-10 microbubbles), grade II (>10 microbubbles but no curtain), and grade III (with curtain).</p><p><b>RESULTS</b>s The positivity rates in diagnosis with AS without VM, AS with VM, ASb without VM, and ASb with VM tests were 10.9%, 23.8%, 12.1% and 25.8%, respectively. AS with VM test had a higher positive rate than AS without VM test (23.8% vs 10.9%, P=0.001), and ASb with VM test had a higher positive rate than ASb without VM test (25.8% vs 12.1%, P=0.001). The positive rates were similar between ASb without VM and AS without VM test (12.1% vs 10.9%, P=0.250) and between ASb with VM test and AS with VM test (25.8% vs 23.8%, P=0.125).</p><p><b>CONCLUSION</b>VM can improve the positive rate of PFO diagnosis in c-TCD examination, and the positive rates are comparable between examinations using the contrast agents AS and ASb.</p>

Effects of recombinant human erythropoietin on brain-derived neurotrophic factor expression in different brain regions of aging rats / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the effect of recombinant human erythropoietin (rhEPO) on expression of brain-derived neurotrophic factor (BDNF) in different brain regions of aging rats.</p><p><b>METHODS</b>Forty male SD rats were randomized equally into negative control group, D-galactose group, EPO treatment group, and positive control group. Rat models of subacute aging were established by continuous subcutaneous injection of 5% D-galactose. Immunohistochemical staining was used to analyze the variation of BDNF expressions in different brain regions of the aging rats with different treatments.</p><p><b>RESULTS</b>Significant brain region-specific differences in BDNF expression were found among the rats in different groups. Compared with those in the negative control group, the numbers of BDNF-positive cells in the hippocampal CA1 region, CA3 region, dentate gyrus (DG) and frontal cortex were all decreased obviously in D-galactose group (P<0.05) but increased in both EPO group and the positive control group (P<0.05) without significant differences between the latter two groups. In the rats in the same group, the number of BDNF-positive cells varied markedly in different brain regions (P<0.05), and the expression level of BDNF was the highest in the frontal cortex followed by the hippocampal CA3 region and the dentate gyrus, and was the lowest in the hippocampal CA1 region.</p><p><b>CONCLUSION</b>Treatment with rhEPO enhances the expression of BDNF in rat neural cells, suggesting that rhEPO may protect the nervous system from aging by regulating the BDNF pathway.</p>