何首乌提取物对人乳腺癌细胞脂肪酸合酶的抑制研究

目的 研究何首乌提取物对人乳腺癌MCF7细胞脂肪酸合酶(fatty acid synthase，FAS)的抑制作用。方法 MTT法测定人乳腺癌MCF7细胞增殖速度，采用超速离心技术部分纯化人乳腺癌MCF7细胞FAS。不同浓度何首乌提取物与FAS相互作用不同时间后，加入底物，用分光光度法观察何首鸟提取物对FAS的抑制作用。结果 何首鸟提取物对人乳腺癌MCF7细胞的增殖有一定的抑制作用。人乳腺癌MCF7细胞FAS被部分纯化，三种浓度何首乌提取物(0．1，0．5，1g／L)与FAS在催化前相互作用0、5和10min，对FAS活性的抑制率分别为24．60％、27．30％、and42．75％(0．1g／L)；43．50％、50．30％、and94．03％(O．5g／L)；98．60％、97．30％ and97．05％(1g／L)。结论 何首乌提取物对人乳腺癌MCF7细胞FAS具有抑制作用；作用强度既依赖于抑制剂浓度，又依赖于抑制剂与酶相互作用时间。     

Inhibitory motor control in children with attention-deficit/hyperactivity disorder: event-related potentials in the stop-signal paradigm.

BACKGROUND: The aim of the study was to investigate the inhibitory control of an ongoing motor response and to identify underlying neural deficiencies, manifested in event-related potentials, that cause poorer inhibitory performance in children with attention-deficit/hyperactivity disorder. METHODS: A stop-signal paradigm with a primary visual task and auditory stop signal was used to compare performance in 13 children with attention-deficit/hyperactivity disorder and 13 control children, while event-related potentials were recorded simultaneously. RESULTS: Children with attention-deficit/hyperactivity disorder showed poorer inhibitory performance through a slower inhibitory process. Inhibitory processing of auditory stop signals was marked by a frontal N2 component that was reduced in the attention-deficit/hyperactivity disorder group relative to controls. A central positive component (P3) was associated with the success of inhibiting a response, but there were no group differences in its amplitude or latency. CONCLUSIONS: Findings support the hypothesis of deficient inhibitory control in children with attention-deficit/hyperactivity disorder. Slower inhibitory processing appears to be due to a specific neural deficiency that manifests in the processing of the stop signal as attenuated negativity in the N2 latency range.     

银耳制剂对小鼠移植性肿瘤预防及其机理的实验研究

小鼠在移植肿瘤细胞前,注射银耳制剂,显示出银耳对荷腹水型或荷实体瘤小鼠肿瘤的生长有明显的抑制作用.正常小鼠给银耳制剂后,其腹腔巨噬细胞(M￠)数量与功能、形态有明显变化,此M￠可吞噬和杀伤肿瘤细胞.     

Glycine-like immunoreactivity in synaptic boutons of identified inhibitory interneurons in the mammalian spinal cord

Glycine is thought ti be a major inhibitory neurotransmitter in the mammalian CNS. Two types of physiologically identified interneurons, Renshaw cells and Ia inhibitory interneurons, were intracellularly staind with horseradish peroxidase, and their axon terminals were studied at the electron microscopic level. Post-embedding immunogold procedures weer used to reveal the presence of glycine-like immunoreactivity. The synaptic terminals of both types of interneuron were significantly enriched with glycine-like immunoreactivity, providing support for the idea that glycine is a mediator of synaptic transmission in the recurrent and reciprocal inhibitory pathways to motoneurons.     

抗癌新药3′,5′-环胞苷二棕榈酸酯脂质体的研究

将3′,5′-环胞苷二棕榈酸酯包封于脂质体中.药效学研究表明,药物的脂质体剂型对腹水型肝癌细胞的抑制率比游离药物以及阿糖胞苷脂质体的抑制率高1倍以上.化学动力学实验显示,在pH为6.9时,脂质体中药物的分解反应速度比游离药物慢得多,其有效期比游离药物长3倍以上.用荧光法研究药物分子在脂双层上的状态,探讨了药物包封于脂质体中抗癌活性及化学稳定性提高的原因.     

纳米抗菌剂抑菌杀菌性能研究

目的：检测纳米抗菌剂对标准菌株的杀菌、抑菌性能和高温对其抑菌效果的影响。方法：目标菌为大肠杆菌、金黄色葡萄球菌和白色念珠菌，通过悬液定量杀灭试验和抑菌环试验检测纳米抗菌剂的杀菌、抑菌能力。结果：水溶性纳米抗菌膜溶于5ml灭菌水中作用l0min可杀灭95．39％的金黄色葡萄球菌和93．28％的白色念珠菌，复合了纳米银的抗菌医用棉条、烧烫伤贴、创伤贴对大肠杆菌和金黄色葡萄球菌的抑菌环直径大于l0mm，对白色念珠菌的抑菌环直径大于7mm。结论：纳米抗菌剂对细菌繁殖体和白色念珠菌具有良好的抑菌、杀菌作用，高压灭菌处理对纳米银抗菌剂抑菌效果影响不大，但织物构造对其抑菌效果有影响。     

焦痂提取液中丙二醛含量对线粒体呼吸及内膜能化作用的影响

大鼠背部20％光辐射Ⅲ度烧伤7天后的焦痂提取液及1:4、1:8稀释液能对正常大鼠肝线粒体呼吸产生明显的抑制作用,相同方法制成的正常皮提取液只呈轻度抑制,1:4稀释液已无抑制作用,两者丙二醛含量相差悬殊,丙二醛含量与抑制率呈相关,但进一步分析表明这种相关为共存现象,丙二醛含量增高不是呼吸率下降的直接原因。丙二醛增高与膜脂双层的破坏有关,内膜能化作用实验表明,当膜脂受到一定程度破坏时,能化作用受到抑制。然而在能化作用未表现异常时,呼吸率已呈一定程度抑制,故呼吸率抑制还受到提取液其他组分的影响。     

The Toxic Effects of Serum from Patients with Type 1 Diabetes Mellitus on Mouse Neuroblastoma Cells: A New Mechanism for Development of Diabetic Autonomic Neuropathy

The pathogenesis of diabetic neuropathy is incompletely understood. The possibility that humoral neurotoxic factors contribute as a cause of diabetic neuropathy was tested by application of serum from patients with Type 1 and Type 2 diabetes to mouse neuroblastoma cells, which have the characteristics of adrenergic neurons in culture. Serum from patients with Type 1 diabetes and somatic neuropathy significantly inhibited both proliferation and differentiation of neuroblastoma cells, while serum from patients with Type 1 diabetes but no symptoms of neuropathy and patients with Type 2 diabetes and neuropathy had no effect on proliferation, and serum from Type 2 patients only marginally inhibited differentiation. The effects of Type 1 diabetic serum could be reversed by pre-absorption of the serum to neuroblastoma cells, and were independent of glucose levels. Immunoglobulins precipitated from the sera mimicked the effects of whole sera. These results suggest that Type 1 diabetes mellitus causes a change in serum composition, possibly related to autoimmunity, that is capable of contributing to adrenergic autonomic neuropathy in diabetic patients.     

白血病相关抑制物对CFU－GM增殖的抑制作用

用半固体双层琼脂培养法，将白血病细胞植入底层，正常ＣＦＵ－ＧＭ植入上层，作白血病细胞与正常ＣＦＵ－ＧＭ的共同培养。结果发现，底层琼脂中加入０．５×１０５／ｍｌ的白血病细胞后，上层琼脂中的ＣＦＵ－ＧＭ从对照组的１９３．５下降至１２３．１／１×１０５个骨髓有核细胞（ＢＭＮＣ），加入底层的白血病细胞增加时，ＣＦＵ－ＧＭ生成进行性受抑制，当植入的白血病细胞数达１５×１０５／ｍｌ时，几乎无ＣＦＵ－ＧＭ生成。此抑制作用亦见于白血病细胞的培养上清液中。量－效关系测定发现，正常ＣＦＵ－ＧＭ培养体系中加入１０％的白血病细胞培养上清液时，ＣＦＵ－ＧＭ生成率从对照纪的１１２．２下降到８８．６／１×１０５ＢＭＮＣ，以后抑制效应不再增加。以上结果揭示，白血病细胞对ＣＦＵ－ＧＭ的抑制是经某种体液因子实现的。     

Synaptic modifications accompanying epileptogenesis in vitro: long-term depression of GABA-mediated inhibition

We used an in vitro model similar to kindling to examine the processes underlying epileptogenesis. A 60 Hz train was applied every 5–10 min to the Schaffer collateral pathways in guinea pig hippocampal slices until epileptiform bursting was elicited in the CA3 region. The resultant alterations in both spontaneous and evoked activities were studied using intracellular recordings from CA3 pyramidal cells. An attempt was made to elucidate the synaptic modifications responsible for the conversion to this state of enhanced excitability. Analyses revealed that the emergence of epileptiform discharge was accompanied by a long-term depression of evoked inhibitory conductances. This tetanus-induced reduction of inhibition involved both the early and late phases of the evoked hyperpolarization, suggesting modification of both the GABA_A and GABA_B receptor-mediated events. Previous studies have suggested that NMDA receptor activation plays an important role in the induction of epileptiform activity in this model. Our data, showing that depression of inhibition can be induced in the presence of CNQX, is consistent with this hypothesis. The parallel development of long-term depression of inhibition and epileptiform bursting following tetanic stimulation suggests that plasticity of the inhibitory transmission process is a potential source of vulnerability contributing to epileptogenesis.