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 …     

1型糖尿病患者谷氨酸脱羧酶反应性T淋巴细胞的测定

目的 探讨糖尿病患者血清中谷酸脱闳酶反应性Ｔ淋巴细胞的阳性反应及临床意义。方法 应用对硝基苯２酰氨基已糖（ＮＡＧ）微量酶反应比色法反映细胞增殖,检测３７例１型糖尿病（ＤＭ）患者外周血单核细胞对谷氨酸脱羧酶（ＧＡＤ）的反应性,并以２型ＤＭ、其他自身免疫性疾病患者及正常人各３０例对照。结果 １型ＤＭ ＧＡＤ反应性Ｔ细胞的阳性率为３５．１％（１３／３０）,其他自身免疫性疾病１０％（３／１０）,而２型ＤＭ     

犬失血性休克早期血浆3种酶活性值的变化

用１０只犬复制失血性休克模型,观察休克前、休克３０ｍｉｎ及回输血后３０ｍｉｎ时,血浆中心肌相关酶—肌酸激酶（ＣＫ）、谷草转氨酶（ＧＯＴ）、α－羟丁酸脱氢酶（ＨＢＤ）活性值的变化。结果发现：失血性休克３０ｍｉｎ时,ＣＫ、ＧＯＴ较休克前显著下降（Ｐ＜０．０５,Ｐ＜０．０１）;ＨＢＤ值也下降,但无统计学意义（Ｐ＞０．０５）。输血后３０ｍｉｎ时,ＣＫ、ＧＯＴ、ＨＢＤ值回升,与休克３０ｍｉｎ时比显著升高（Ｐ＜０．０５）,与休克前比无显著性差别（Ｐ＞０．０５）。提示：失血性休克早期心肌细胞可能存在有一种保护性反应,心肌细胞没有发生明显损伤。     

复方沙棘颗粒对大鼠皮层神经细胞缺血性损伤的保护作用

目的 :研究复方沙棘颗粒对体外培养的大鼠大脑皮层神经细胞谷氨酸 (Glu)损伤的保护作用及机理。方法 :分离培养新生 (1d)大鼠大脑皮层神经细胞 ,加入Glu模拟兴奋性损伤 ,MTT法测定细胞存活率 ,比色法测定上清中乳酸脱氢酶 (LDH)含量 ,细胞中超氧化物歧化酶 (SOD)、谷胱甘肽 (GSH Px)活性、丙二醛 (MDA)含量。结果 :细胞经Glu损伤后 ,上清LDH含量、细胞中MDA含量显著增加 ,SOD和GSH Px活力明显下降。复方沙棘处理组可有效防止上述改变。结论 :复方沙棘颗粒可有效保护由Glu引起的大鼠大脑皮层神经细胞的损伤。其机理可能与抗脂质过氧化、清除自由基有关     

Synthesis of poly(glutamic acid)-tyramine hydrogel by enzyme-mediated gelation for controlled release of proteins

An in situ-formed hydrogel was synthesized by enzymatic cross-linking of poly(γ-glutamic acid)–tyramine conjugates (PGA–Tyr) using horseradish peroxidase (HRP) and hydrogen peroxide (H₂O₂). The gelation time ranged from 25 s to 5 min was accomplished by tuning the concentration of HRP, H₂O₂/Tyr molar ratio and the degree of substitution (DS) of Tyr groups. The storage modulus (G′), cross-link density, and mesh size can be tailored by controlling the H₂O₂/Tyr ratio and DS. The rheological analysis indicated that the storage modulus (G′) can be tailored from approximately 40 to over 1100 Pa with the increasing H₂O₂/Tyr ratio and DS. The bovine serum albumin (BSA) was used as model protein and encapsulated into the hydrogel during the enzyme-mediated cross-linking reaction. Controlled release of BSA in vitro from the PGA–Tyr hydrogel was obtained. The release rate and cumulative release amount of encapsulated BSA were manipulated by controlling the H₂O₂/Tyr ratio and DS. More than 90% of encapsulated BSA was released from the hydrogel with low cross-link density and lager mesh size in 60 h, while only 68% of BSA was released from the hydrogel with high cross-link density and small mesh size. The results indicated that the PGA–Tyr hydrogel is a promising material for the controlled release of therapeutic protein or peptides.     

疏血通注射液对缺氧缺糖后星形胶质细胞内谷氨酸清除的影响

脑血管闭塞后,神经元突触前膜释放的谷氨酸无法很快的被突触后膜转运,导致在神经元外部的谷氨酸大量聚集[1]。星形胶质细胞可通过兴奋性氨基酸转运蛋白2(excitatory amino acid transporters 2,EAAT2)清除过量的谷氨酸[2]。有研究表明,EAAT2在急性缺血性脑中风时的表达大量减少,而增加EAAT2的表达可对神经产生保护作用[3]。     

Distribution and intrinsic membrane properties of basal forebrain GABAergic and parvalbumin neurons in the mouse

The basal forebrain (BF) strongly regulates cortical activation, sleep homeostasis, and attention. Many BF neurons involved in these processes are GABAergic, including a subpopulation of projection neurons containing the calcium‐binding protein, parvalbumin (PV). However, technical difficulties in identification have prevented a precise mapping of the distribution of GABAergic and GABA/PV+ neurons in the mouse or a determination of their intrinsic membrane properties. Here we used mice expressing fluorescent proteins in GABAergic (GAD67‐GFP knock‐in mice) or PV+ neurons (PV‐Tomato mice) to study these neurons. Immunohistochemical staining for GABA in GAD67‐GFP mice confirmed that GFP selectively labeled BF GABAergic neurons. GFP+ neurons and fibers were distributed throughout the BF, with the highest density in the magnocellular preoptic area (MCPO). Immunohistochemistry for PV indicated that the majority of PV+ neurons in the BF were large (>20 μm) or medium‐sized (15–20 μm) GFP+ neurons. Most medium and large‐sized BF GFP+ neurons, including those retrogradely labeled from the neocortex, were fast‐firing and spontaneously active in vitro. They exhibited prominent hyperpolarization‐activated inward currents and subthreshold “spikelets,” suggestive of electrical coupling. PV+ neurons recorded in PV‐Tomato mice had similar properties but had significantly narrower action potentials and a higher maximal firing frequency. Another population of smaller GFP+ neurons had properties similar to striatal projection neurons. The fast firing and electrical coupling of BF GABA/PV+ neurons, together with their projections to cortical interneurons and the thalamic reticular nucleus, suggest a strong and synchronous control of the neocortical fast rhythms typical of wakefulness and REM sleep. J. Comp. Neurol., 521:1225–1250, 2013. © 2012 Wiley Periodicals, Inc.     

早期帕金森病患者血浆谷氨酸、天冬氨酸和γ-氨基丁酸水平的改变及其诊断价值的研究

目的探索早期帕金森病(PD)患者血浆谷氨酸、天冬氨酸和γ-氨基丁酸(GABA)水平的改变及其潜在的早期诊断价值。方法选择病程3年的早期PD患者52例(早期PD组),年龄性别与PD组匹配的健康对照者52名(对照组),采用高效液相色谱-荧光检测法(HPLC-RF)检测所有研究对象的血浆谷氨酸、天冬氨酸和GABA水平,并量化分析两组间差异。运用受试者特征曲线(ROC)评价血浆氨基酸神经递质识别早期PD的能力。采用Spearman秩相关分析血浆氨基酸神经递质水平和早期PD患者临床特征的关联。结果早期PD组的血浆谷氨酸、天冬氨酸和GABA水平均明显低于对照组。ROC分析提示3种氨基酸均可以有较高的敏感度(76.9%~100%)和特异度(59.6%~100%)识别早期PD和健康者。相关性分析提示血浆天冬氨酸、GABA水平和早期PD患者的临床特征密切相关。结论血浆氨基酸神经递质水平下降是早期PD患者的外周生化基础的一部分,可以为PD的早期识别提供一些帮助。