GA-BP网络在谷氨酸菌体浓度软测量中的应用

针对菌体细胞浓度是影响谷氨酸发酵过程重要的生物参数,而其在线实时检测难以实现的状况,采用遗传算法和BP神经网络相结合的方法(GA-BP网络)对其进行软测量。通过对谷氨酸生产工艺过程的分析,找到影响菌体细胞浓度的过程参数,从现场历史数据中选取样本,建立软测量模型。仿真结果表明:新方法可以避免单独使用BP网络陷入局部最小的问题,能加快全局收敛速度,对谷氨酸发酵过程菌体浓度的软测量效果更好。     

Double Labeling Immulloelectron Microscopic Study on the Synaptic Connections between Glutamic Acid Neurons and GABA Neurons in the Hippocampus of Rats

The pathogenesis of epilepsy is a very complicated process, In which neurotransmltters play important roles. The hippocamplls is a frequently attacked site and an ideal model tissue for epilepsy' l]. In general, the seizure results from the imbalance of excitation and inhibition, i. e., increased effect of excltatory neurotransmltters ordecreased effect of inhlbitory neurotransrnlttersL =' ']. However, there was no nlorphologlcal, eel)eclally at the ultrastructural level, evidenceic identify …     

Conditioned-medium of stem cells from human exfoliated deciduous teeth prevent apoptosis of neural progenitors

PurposeThis study aimed to evaluate the neuroprotective ability of the conditioned medium of stem cells from human exfoliated deciduous teeth (CM-SHED) to prevent glutamate-induced apoptosis of neural progenitors.Materials and methodsNeural progenitors were isolated from two-day-old rat brains, and the conditioned medium was obtained from a mesenchymal stem cell SHED. Four groups were examined: neural progenitor cells cultured in neurobasal medium with (N + ) and without (N-) glutamate and glycine, and neural progenitor cells cultured in CM-SHED with (K + ) and without (K-) glutamate and glycine.ResultsThe expression of GABA A1 receptor (GABAAR1) messenger RNA (mRNA) in neural progenitor measured by real-time quantitative PCR. GABA contents were measured by enzyme-linked immunosorbent assay, whereas the apoptosis markers caspase-3 and 7-aminoactinomycin D were analysed with a Muse® cell analyzer. The viability of neural progenitor cells in the K + group (78.05 %) was higher than the control group N- (73.22 %) and lower in the N + group (68.90 %) than in the control group. The K + group showed the highest GABA content, which significantly differed from that in the other groups, whereas the lowest content was observed in the N + group. The expression level of GABAAR1 mRNA in the K + group was the highest compared to that in the other groups. CM-SHED potently protected the neural progenitors from apoptosis.ConclusionsCM-SHED may effectively prevent glutamate-induced apoptosis of neural progenitors.     

3种恶性疟原虫红内期抗原基因的测序和序列分析

目的　测定我国恶性疟原虫海南株 (FCC1/ HN)谷氨酸富集蛋白 (GARP)、丝氨酸重复抗原 (SERA)和裂殖子表面蛋白 1(MSA1)基因序列 ,并进行序列分析。　方法　采用 PCR技术从恶性疟原虫 FCC1/ HN株基因组 DNA中扩增 GARP、SERA和 MSA1基因片段 ,分别插入到测序载体上进行测序。应用 DNAstar软件辅助分析 3种抗原基因的结构及 3种抗原在不同恶性疟原虫株间的分化情况。　结果　恶性疟原虫 FCC1/ HN株 GARP基因全长 2 2 6 3bp,编码6 82个氨基酸残基 ,谷氨酸占 2 3.6 1% ,包含 5个典型的氨基酸重复序列 ;SERA基因全长 344 8bp,编码 995个氨基酸残基 ,丝氨酸含量为 10 .6 5 % ,包含 1个连续 32个丝氨酸 (S)残基的序列 ;MSA1基因全长 5 0 85 bp,编码 16 94个氨基酸残基 ,MSA1的氨基酸序列符合 MAD2 0型特征。恶性疟原虫 FCC1/ HN株与 3D7、FC2 7株 GARP的序列差异主要集中于 C-末端 ;FCC1/ HN株与 FCR3、3D7、FCBR、Hondulas- 1株 SERA的序列差异主要集中于 N-端。FCC1/ HN株与MAD2 0、3D7、HN1、HN2、FC2 7、RO- 71、RO- 33、CAMP和 Palo- alto株 MSA1的同源性高 ,K1和 WEL L COME株 MSA1的同源性高 ,各分离株 MSA1的序列差异主要处于第 2至 16分区。　结论　了解了恶性疟原虫 FCC1/ HN株 GARP、SERA和 MSA1的     

二次脑损伤后鼠脑皮层代谢性谷氨酸受体5mRNA表达改变及α-甲基-4-羧基苯丙氨酸的治疗作用

目的 研究二次脑损伤后鼠脑皮层代谢性谷氨酸受体5(mGluR5)mRNA的变化及I类mGluR5拮抗剂α－甲基－4－羟基苯丙氨酸（MCPG）的作用。方法 90只SD大鼠随机分为原位杂交组（60只）和MCPG作用组（30只）,每组又分为不同的亚组。在Marmarou大鼠加速性弥漫性脑损伤模型基础上,采用血造成低血压。在伤后不同时间进行原位杂交和病理学研究。结果 单纯脑损伤后脑皮层mGR5mRNA于伤后1d开始降低,7d最低（P＜0．05）;而脑损伤合并二次脑损伤后脑皮层mGluR5mRNA水平在伤后变化更明显。I类mGluRs拮抗剂MCPG可减少二次脑损伤后的损伤神经元的数目。结论 脑损伤可以抑制mGluR5的表达和生成,其作用可能与mGluR1、mGluR1α不同,对神经元具有保护作用。     

Inhibition of quisqualate-induced seizures by glutamic acid diethyl ester and anti-epileptic drugs

Summary Glutamic acid diethyl ester (GDEE) is a glutamate antagonist which acts preferentially at the quisqualate-sensitive receptor and has been shown to be an effective anticonvulsant in alcohol withdrawal and homocysteine-induced seizures but ineffective in other seizure models. To better characterize the role of the quisqualate-sensitive receptor in the generation of seizures, quisqualate was administered to mice by intracerebroventricular (ICV) route and immediate onset generalized seizures were observed. The anticonvulsant properties of GDEE and commonly used antiepileptic drugs (AEDs) were investigated with this seizure model. GDEE given by intraperitoneal blocked quisqualate-induced seizures dose-dependently. Diphenylhydantoin (50 mg/kg IP), carbamazepine (50 mg/kg IP), diazepam (1; 4 mg/ kg IP), phenobarbital (40; 80 mg/kg IP), and valproic acid (250; 340 mg/kg IP) were also administered prior to quisqualate-seizure induction. Only valproic acid blocked seizures at nonsedating doses. The GABA transaminase inhibitor aminooxyacetic acid (20 mg/kg IP) was ineffective, suggesting that here valproic acid is active at excitatory receptors rather than by potentiating GABA post-synaptic inhibition. These data are consistent with the hypothesis that the quisqualate-sensitive receptor is involved in some forms of clinically observed seizures, particularly those which are controlled by valproic acid.     

Glutamic acid in treatment of alcohol intoxication aggravated by ecologically unfavorable factors

Alcohol intoxication aggravated by exposure to ecologically unfavorable factors (methanol and furfural vapors) induced pronounced desynchronization of hematologic processes, dramatic disturbance of carbohydrate metabolism, and considerable structural changes in internal organs. Treatment with glutamic acid reduced pathological manifestations and increased the adaptive capacities of the organism. Functional and morphological changes observed in laboratory animals after treatment with the neurometabolic compound glutamic acid could be classified as reversible. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 129, No. 3, pp. 321–325, March, 2000     

Synthesis and characterization of a series of novel glutamic γ-15N-anilide dipeptides

The preparation of a series of novel Cbz–Gln–Gly dipeptide derivatives is reported, wherein the γ-carboxamide groups of the glutamine side chains have been modified to γ-¹⁵N-anilides which are substituted in the para position with -NO₂, -Cl, -H, -CH₃, -OCH₃, and -N(CH₃)₂. Characterization of the free anilines (pK_a values and ¹⁵N NMR chemical shifts) and corresponding γ-anilides (¹⁵N NMR chemical shifts and FTIR wavenumbers) is also reported. Correlation of these physicochemical data to Hammett substituent parameters (σ_para) is discussed. These novel dipeptide derivatives should prove to be generally useful for structure–function enzymology studies of γ-glutamyl transferring enzymes.     

Excitability changes induced in the striatal dopamine-containing terminals following frontal cortex stimulation

The excitability of the dopamine-containing terminal field in the striatum (St) following frontal cortex (FC) stimulation was investigated in halothane-anesthetized rats. Either glutamic acid (GLU, 6.2 mM) or square pulses (a train of 25 pulses, 500-800 microA/0.3 ms: 1 Hz/20 s) were used to stimulate FC. To stimulate St monophasic square wave pulses (10-4000 microA/0.5 ms/1 Hz) were delivered. Excitability was measured by determining the threshold for antidromic activation of substantia nigra cells. Threshold was defined as the minimum current required for antidromic invasion of the cell on 100% of non-collision trials. The mean threshold current was 1029 +/- 167 microA. Following FC stimulation a significant decrease (30%) in excitability was observed in most cases (80%). No correlation between firing rate and threshold fluctuations was observed. It is concluded that FC activity decreases the excitability of the dopaminergic nigrostriatal terminal field. Whether this is a direct or an indirect effect is discussed.     

醋酸锌对谷氨酸诱导的小鼠脑片即早基因过度表达的抑制作用

目的：探讨谷氨酸对脑组织即早基因表达的影响以及醋酸锌对谷氨酸诱导c-fos和c-jun过度表达的拮抗作用。方法：体外小鼠海马脑片培养；在培养基中加入200μmol/L的谷氨酸（或同时加入谷氨酸和醋酸锌），作用0.5,1,2,3h，然后进行RT-PCR实验，检测c-fos和c-jun的表达变化。结果：200μmol/L谷氨酸处理的脑片中，1-2h期间c-fos的表达升高，当谷氨酸与100μmol/L醋酸锌共同处理脑片时，1-3h期间c-fos表达基本恢复正常；200μmol/L谷氨酸作用下，脑片c-jun表达水平从0.5h起即明显升高，谷氨酸与醋酸锌共同作用时，可见c-jun基因在各检测时段表达基本接近正常。结论：谷氨酸可引起c-fos及c-jun的过度表达，锌离子可拮抗谷氨酸诱导的c-fos和c-jun过度表达作用，使二基因表达恢复正常。