Quisqualate lesions of rat NBM: Selective effects on working memory in a double Y-maze

Some authors have reported that quisqualic acid lesions of the nucleus basalis magnocellularis (NBM), although producing large cortical cholinergic losses, have little effect on memory. The purpose of the present study was to investigate the effects of quisqualic acid lesions of the NBM on working and reference memory in a double Y-maze. Each trial started with placement into one of the two end arms of the first Y-maze, and the correct response was to go down the stem (reference memory). Access was then given to the second Y-maze, the correct response being conditional upon the side of the first Y-maze from which that trial had begun (working memory). Rats were trained to an 88% correct criterion and were then given either bilateral quisqualic acid (60 nM, 0.5 microliters) or sham lesions (0.9% saline, 0.5 microliters) of the NBM. One week postsurgery, rats were tested on the double Y-maze task with delays of 0, 5 or 30 seconds being introduced prior to both the working and reference memory choice. NBM lesions produced a 63.2 +/- 6.2% decrease of cortical choline acetyltransferase (ChAT) compared to unoperated controls. Delays affected only the working memory of the sham group. Rats with lesions showed a significant impairment of working memory at all delays, but no change in reference memory. Results indicate that quisqualic acid lesions of the NBM that produce significant reductions in cortical ChAT selectively impair working memory.     

Neurobiology of Bipolar Illness: Implications for Future Study and Therapeutics

Many findings implicating prefrontal cortical and limbic areas of the brain and endocrine systems in the neuropathology and pathophysiology of bipolar illness have greatly increased our understanding of the neurobiology of the illness. New imaging techniques such as PET, MRI, SPECT, and MRS have detailed more evidence of specific regional alterations in the brains of bipolar patients than was thought possible just 20 years ago. These methods are beginning to be used to help predict response to treatment. Examining the mechanisms of action of mood stabilizers (such as lithium, carbamazepine, and valproate) has provided clues to potential underlying neurobiological abnormalities in the illness. Recent studies of postmortem brain tissue have begun to confirm prefrontal cortical and limbic neurochemical and microstructural alterations in patients with bipolar illness compared with controls. It is postulated that it is the balance between primary pathological versus secondary adaptive alterations in gene expression in the illness and their enhancement or dampening by pharmacotherapy, that may determine the episodic course of mood fluctuations and remissions. Further examination of the pathophysiology and neurobiology of bipolar illness should lead to both more effective treatments and, potentially, secondary and even primary episode prevention.     

Effects of a Broad-spectrum Behavioral Medicine Treatment Program on Children with Refractory Epileptic Seizures: An 8-Year Follow-Up

We present an 8 year follow-up on a group of children with refractory epileptic seizures who participated in the early 1980s in a controlled group study on the effects of a broad-spectrum behavior modification treatment program on children with refractory epileptic seizures. In the original study, 18 children were divided into three groups: behavior modification group, attention control group, and control group. The purpose was to investigate the effects of a learning-based treatment program superimposed on a regular medical treatment program. Also, the effects of professional attention were evaluated. At the 10 week and 1 year follow-ups, only the group receiving the behavior modification intervention had a significantly reduced rate of seizure index. The present study investigates these same children 8 years later using the same methods of investigation for an additional 10 week period. The results indicate that a significant reduction in seizures was obtained only for the behavior modification group at the 8 year follow-up.     

The effects of a reduced exercise duration taper programme on performance and muscle enzymes of endurance cyclists

Summary The influence of tapering on the metabolic and performance parameters in endurance cyclists was investigated. Cyclists (n = 25) trained 5 days · week^–1, 60 min·day^–1, at 75–85% maximal oxygen consumption (VO_2max) for 8 weeks and were then randomly assigned to a taper group: 4D (4 days;n = 7), 8D (8 days;n = 6), CON (control, 4 days rest;n = 6), NOTAPER (non-taper, continued training;n = 6). Muscle biopsy specimens taken before and after training and tapering were analysed for carnitine palmityltransferase (CPT), citrate synthase, ß-hydroxyacyl CoA dehydrogenase (HOAD), cytochrome oxidase (CYTOX), lactate dehydrogenase, glycogen and protein. Significant increases inVO_2max (6%), a 60-min endurance cycle test (34.5%), oxidative enzymes (77–178%), glycogen (35%) and protein (34%) occurred following training. After the taper, HOAD and CPT decreased 25 % (P<0.05) and 26% respectively, in the CON. Post-taper CYTOX values were different (P<0.05) for 4D and 8D compared with CON. Muscle glycogen levels were increased (P<0.05) after tapering in the 4D, 8D and CON, but decreased in NOTAPER. Similarly, power output at ventilation threshold was significantly increased in the 4D (27.4 W) and 8D (27 W) groups, but decreased (22 W) in the NOTAPER. These findings suggest that tapering elicited a physiological adaptation by altering oxidative enzymes and muscle glycogen levels. Such an adaptation may influence endurance cycling during a laboratory performance test.     

曲肘式机构的优化设计

以功效系数为目标函数,相应地确定了设计变量和约束函数,对塑料注塑机合模机构的参数进行优化计算,提高了机构的综合性能。     

增生性玻璃体视网膜病变基质金属蛋白酶的定量研究

目的:研究增生性玻璃体视网膜病变(proliferative vitreoretinopathy,PVR)玻璃体中基质金属蛋白酶(matrix metalloproteinases,MMPs)的表达,探讨MMPs在PVR病理过程中的作用。方法:PVR患者采用标准三切口巩膜扁平部玻璃体切割术(pars plana vitrectomy,PPV),取未稀释的玻璃体21只眼,PPV术后复发的玻璃体腔液20只眼,意外死亡的正常人玻璃体10只眼,采用明胶酶谱分析法定量分析MMP-2和MMP-9活性水平。结果:PVR玻璃体有MMP-2活性水平增高,与正常玻璃体比较差异有显著性意义(P<0.05)。21眼PVR玻璃体中13只眼有MMP-9活性水平增高,平均(171.52±13.17)扫描单位。20眼PPV术后PVR复发的玻璃体腔液19只眼有MMP-9活性水平增高,平均(156.01±37.21)扫描单位。正常人玻璃体无MMP-9的表达。结论:PVR玻璃体有MMP-2和MMP-9活性水平增高,MMP-9活性水平增高可能与术后PVR复发有关。眼科学报2003;19:130-132。     

流化床喷雾制粒机若干机理的研究

研究了流化床喷雾制粒机的起始流化速率，粉粒平稳流化及其控制方法，喷雾制粒机理和骤变失稳现象，指出起始流化速度的实验值远大于理论值，但是可以通过对床层压降的监控，实现平稳流化的操作控制，颗粒以团骤方式长大，而温骤变失稳是本文流化制粒失效的主要形式，讨论了多种过程参量对制粒和骤变失稳的影响，其结果有助于指导实际生产。     

脉冲激光射线强化金属材料的几个问题

本文讨论了激光脉冲射线强化金属材料的几个问题:强化图形,材料性能,加工用量及表面涂层对被强化表面性能的影响。     

大鼠子宫内膜抗菌成分的初步分析

作者以１％乙酸冲洗ＳＤ大鼠子宫内膜，获得子宫内膜酸溶性提取物。利用琼脂糖弥散法和电泳凝胶琼脂糖弥散法抗菌试验发现，子宫内膜提取物有三条主蛋白带对致病性大肠杆菌ＭＬ－３５Ｐ耐药株有强抗菌活性，这三条抗菌蛋白带命名为ＲａｔＵＰ－１，ＲａｔＵＰ－２和ＲａｔＵＰ－３，分别占子宫内膜提取物总蛋白量的４．５％，５．７％和６．６％。虽然提取物存在溶菌的活性，但其含量甚微，在ＡＵ一ＰＡＧＥ图谱上亦未能显现溶菌酶条带。本实验的结果提示子宫内膜合成一类抗菌多肽，可能在子宫抗菌机制中发挥重要作用。