脑缺血时谷氨酸释放机制

谷氨酸是中枢神经系统主要的兴奋性神经递质,在脑缺血造成的神经元损伤过程中发挥重要作用。脑缺血时多种机制参与了谷氨酸释放的的调节,如Ca2+依赖性的出胞式释放、谷氨酸转运体调节的释放、水肿诱发的释放和受体调节的释放等。本文根据现有的文献资料,综述了脑缺血时谷氨酸释放机制。     

γ-亚麻酸乙酯的合成研究

目的确定合成γ 亚麻酸乙酯的最佳工艺路线。方法以黑加仑油为原料采用尿素包和、柱色谱法、酸催化法等联合方法分离及合成γ 亚麻酸乙酯。结果确定黑加仑油经 2～ 3次尿素包和 ,反应温度 80℃ ,反应时间90min ,3%盐酸作酸性溶媒 ,乙醇和γ 亚麻酸比例为 3∶1的制备工艺。结论酸催化法合成γ 亚麻酸乙酯工艺简便 ,易于操作 ,产品收率高、稳定性好。     

长链非编码RNA TUSC8调控miR-137对宫颈癌迁移和侵袭的影响

【摘要】 目的 探讨长链非编码RNA TUSC8调控miR 137对宫颈癌迁移和侵袭的影响及其机制。方法 qPCR检测TUSC8和miR 137在宫颈癌组织和正常宫颈组织中的表达情况及差异,分析TUSC8与宫颈癌患者临床病理学参数之间的相关关系,双荧光素酶报告基因检测TUSC8与miR 137之间的相互作用;Transwell侵袭实验检测抑制TUSC8后宫颈癌细胞侵袭行为的变化情况;划痕愈合实验检测抑制TUSC8后宫颈癌细胞迁移行为的变化情况;裸鼠体内成瘤实验抑制TUSC8后宫颈癌细胞的成瘤能力的变化。结果 与正常宫颈组织相比,宫颈癌组织中TUSC8和miR 137的表达水平均相对上调,差异有统计学意义（P＜005）;TUSC8的表达与宫颈癌的病理分期相关以及淋巴结转移情况有关,分期越高,TUSC8在宫颈癌组织中表达越高,淋巴结转移的患者中TUSC8的表达也相对较高;双荧光素酶实验证实TUSC8能与miR 137的3’ UTR特异性结合,可以调控miR 137的表达与活性;抑制TUSC8的表达后可以抑制宫颈癌细胞的迁移和侵袭能力;抑制TUSC8后宫颈癌细胞的成瘤能力受到相应的抑制。结论 TUSC8可以调控miR 137的表达影响宫颈癌细胞的迁移和侵袭行为。     

The Activity of β-Hexosaminidase (uHex) and γ-Glutamyl-Transferase (uGGT) in Urine as Non-Invasive Markers of Chronic Alcohol Abuse: I. Alcohol-Dependent Subjects

It has been demonstrated that in alcohol-dependent men the uHex test is one of the most powerful discriminating tools, while uGGT has a discriminating power similar to that of sHex but worse than that of uHex, sGGT and s%CDT. Receiver Operating Characteristic (ROC) areas under the curves (AUC) for uHex, uGGT, s%CDT, sHex and sGGT were 0.92, 0.79, 0.88, 0.79 and 0.92, respectively. Due to their good parameters, low cost, ease of use and noninvasive character the uHex and uGGT tests are useful tools for the detection of chronic alcohol abuse.     

Mutational effects of γ-rays and carbon ion beams on Arabidopsis seedlings

To assess the mutational effects of radiation on vigorously proliferating plant tissue, the mutation spectrum was analyzed with Arabidopsis seedlings using the plasmid-rescue method. Transgenic plants containing the Escherichia coli rpsL gene were irradiated with γ-rays and carbon ion beams (320-MeV ¹²C⁶⁺), and mutations in the rpsL gene were analyzed. Mutant frequency increased significantly following irradiation by γ-rays, but not by 320-MeV ¹²C⁶⁺. Mutation spectra showed that both radiations increased the frequency of frameshifts and other mutations, including deletions and insertions, but only γ-rays increased the frequency of total base substitutions. These results suggest that the type of DNA lesions which cause base substitutions were less often induced by 320-MeV ¹²C⁶⁺ than by γ-rays in Arabidopsis seedlings. Furthermore, γ-rays never increased the frequencies of G:C to T:A or A:T to C:G transversions, which are caused by oxidized guanine; 320-MeV ¹²C⁶⁺, however, produced a slight increase in both transversions. Instead, γ-rays produced a significant increase in the frequency of G:C to A:T transitions. These results suggest that 8-oxoguanine has little effect on mutagenesis in Arabidopsis cells.     

Partial regulation of serotonin transporter function by γ-synuclein

Human α-synuclein (α-Syn) is instrumental in maintaining homeostasis of monoamine neurotransmitters in brain, through its trafficking, and regulation of the cell surface expression and, thereby, activity of dopamine, serotonin and norepinephrine transporters. Here we have investigated whether other members of the synuclein family of proteins, γ-synuclein (γ-Syn) and β-synuclein (β-Syn) can similarly modulate the serotonin transporter (SERT). In Ltk⁻ cells co-transfected with SERT and γ-Syn, γ-Syn reduced [³H]5-HT uptake, in a manner dependent on its expression levels. The decrease in SERT activity was via decreased V_max of the transporter, without change in K_m, compared to cells expressing only SERT. By contrast, β-Syn co-expression failed to alter SERT uptake activity, and neither the V_max nor the K_m was changed in the presence of β-Syn. γ-Syn modulation of SERT was only partial, with a maximal ∼27% decrease in SERT activity seen even at high expression levels of γ-Syn. By contrast, α-Syn attenuated SERT activity by ∼65% at identical expression levels as γ-Syn. Co-immunoprecipitation studies showed the presence of heteromeric protein:protein complexes between γ-Syn or α-Syn and SERT, while β-Syn failed to physically interact with SERT. Both α-Syn and γ-Syn colocalized with SERT in rat primary raphae nuclei neurons. These studies document a novel physiological role for γ-Syn in regulating 5-HT synaptic availability and homeostasis, and may be of relevance in depression and mood disorders, where SERT function is dysregulated.