小儿脑立体定向术麻醉应注意的几个问题

本文对我院１９８８～１９９６年６月１０５例脑立体定向手术患儿（ＡＳＡⅠ～Ⅱ，平均年龄９．７９±３．６８岁，男／女：６１／４４）的麻醉资料进行了分析。结果表明，所有患儿均在局麻（０．５％普鲁卡因）基础上进行手术（手术时间１．２～４．５ｈ）．其中辅用镇静剂（安定、氟哌啶）或基础麻醉（肌注氯胺酮或哌替啶）５４例（５１．４％）、静脉麻醉４６例（４３．８％）和气管内麻醉５例（４．８％）。术中最常见的并发症为恶心呕吐（２４例）、窦性心动过速（１０例）／过缓（２４例）和不同程度的呼吸困难（２９例）。为提高手术麻醉的安全性，对围手术麻醉期应注意的几个问题，如术前用药、术中并发症处理、术中监测等进行了讨论。     

Sites and mechanisms for nicotine's action in the brain

A variety of pharmacologic, behavioral, and receptor-binding studies were performed in an effort to determine the mechanism and site of action of nicotine on the rat brain. When nicotine was given into the lateral or fourth ventricles or directly into the lateral vestibular nuclei of rats, it produced a characteristic prostration often accompanied by tonic seizures and body rotation along a longitudinal axis. Of a variety of brain areas studied, the prostration response could only be elicited from the lateral and, to a lesser extent, medial vestibular nuclei. The response could not be produced by a variety of cholinergic agonists or antagonized with nicotinic cholinergic antagonists, with the possible exception of mecamylamine. A good correlation was observed between the ability of nicotine analogues to antagonize the nicotine-induced prostration and their ability to compete with ³H-nicotine binding to rat brain membranes. ³H-nicotine binding had a high affinity, was stereoselective and concentrated in nerve endings and such brain regions as the thalamus, cerebrum, and hippocampus. When nicotine was administered intraventricularly to rats, it significantly elevated the threshold to an aversive shock. It was concluded that many of the central actions of nicotine could not be explained on the basis of traditional nicotinic cholinergic mechanisms.     

Intracranial and orbital hydatid cysts

Summary Parasitic diseases involving brain and orbit are relatively rare in Tunisia; the most frequently encountered is the hydatid cyst, 55 examples of which were seen since CT scanning was introduced into Tunisia 2 years ago. Various aspects of the intracerebral and orbital hydatid cysts are reported and a tentative classification is made based on characteristics revealed by CT.     

青年抑郁症患者脑的3D ^1H MRS和DTI应用研究

目的探讨抑郁症患者脑内可能存在的神经生化代谢异常和细微结构改变。方法对54例首发青年抑郁症患者应用三维磁共振氢质子波谱（3D ^1H MRS）检查,测量脑内多个部位的N-乙酰天门冬氨酸（NAA）、胆碱复合物（Cho）、肌醇（mI）和肌酸（Cr）等代谢物含量的绝对值,并计算NAA、Cho、mI与Cr的比值。同时进行扩散张量成像（DTI）的表观扩散系数（ADC）和各向异性分数（FA）的检测,并与50名健康对照者作比较。结果（1）抑郁症患者的前额叶扣带回皮质、豆状核和尾状核头部的Cho、mI绝对值及Cho/Cr、mI/Cr比值明显高于健康对照组（P均〈0.05）;（2）抑郁症组的额叶白质、胼胝体膝部和体部的ADC值明显高于健康对照组,FA值明显低于健康对照组（P〈0.01）。（3）3D ^1H MRS、DTI单独检测的敏感性分别为88.9%、79.6%,两者联合应用敏感性达92.6%。结论青年抑郁症患者脑内可能存在多个部位的微细结构和神经生化改变,3D ^1H MRS和DTI检测指标可考虑作为抑郁症的客观参考诊断标准之一。     

三维脑白质纤维束示踪成像

目的使用磁共振弥散张量成像数据三维示踪大脑白质纤维束。方法对18名健康自愿者使用弥散加权-回波平面成像(DW-EPI)序列进行头部DTI检查。输出DICOM格式的DTI图像数据并根据已知的脑白质纤维束的解剖学知识,选取起始区、目标区、回避区,使用Diffusion Tensor VisualizerⅡ软件进行脑白质纤维束示踪三维重建。结果大脑的连合系、联络系和投射系的各种脑白质纤维束的结构和其在三维空间的走行可在每例实验对象的三维示踪结果显示,与解剖学所描述相对比基本一致。结论使用三维脑白质纤维束示踪成像可以在活体立体直观地显示大脑的各种脑白质纤维束。不仅可以用于解剖学教学,还对临床神经系统疾病的辅助诊断和科学研究有潜在的应用价值。     

Differential Na+ channel β1 subunit mRNA expression in stellate and flat astrocytes cultured from rat cortex and cerebellum: A combined in situ hybridization and immunocytochemistry study

Astrocytes have been shown to express voltage-sensitive Na⁺ channels, but the molecular structure of these channels is not yet known. Recent studies have demonstrated the expression of rat brain voltage-sensitive Na⁺ channel mRNAs in astrocytes. In this study, we used a combined non-radioactive in situ hybridization immunocytochemistry method to investigate the expression of voltage-sensitive Na⁺ channel ß1 subunit (Naß1) mRNA in definitively identified, GFAP-positive astrocytes cultured from two different regions of the rat brain, cerebrum and cerebellum. In general, two morphologically distinct types of GFAP-positive astrocytes were observed in culture: flat, fibroblast-like and stellate, process-bearing. We observed a differential expression ofNaß1 mRNA in GFAP-positive astrocytes: (1) stellate astrocytes expressed Naß1 mRNA, although the level of Naß1 mRNA expression was variable, and (2) flat astrocytes generally did not express Naß1 mRNA. Moreover, Bergmann-like cells from cerebellum did not express Naß mRNA, while the granule cells associated with Bergmann-like cell expressed Naß mRNA. These observations indicate that Naß mRNA is differentially expressed in rat astrocytes with various morphologies in vitro. © 1995 Wiley-Liss, Inc.     

ASA-601TS型温控热凝射频仪对免脑毁损灶形成的实验研究

目的探讨ASA-601TS型温控热凝射频仪对免脑组织毁损灶形成,以了解毁损灶的形成大小与时间、温度的关系以及温控热凝射频仪相关性能.方法利用ASA-601TS型温控热凝射频仪和外裸长4mm、直径1.6mm热敏电极,对70只成年兔脑组织进行温控热凝毁损实验,测量毁损灶的大小以及常规病理学检查.结果单极毁损灶为类圆形,在70℃时,随着时间的延长从30秒、60秒、90秒,坏死灶直径分别为3.4±0.3mm、5.2±0.4mm、5.8±0.2mm;75℃毁损时间为30秒、60秒、90秒,毁损坏死灶分别为3.7±0.4mm、5.7±0.3mm、6.5±0.5mm,呈逐渐增大;而在45℃时,不管如何延长毁损时间,均不能造成大范围坏死区.因此,45℃以下,可作为可逆性毁损时选择的温度.在电极直径大小不变时,在一定时间内毁损形成的范围与温度、时间呈正相关,但当温度达到75℃时,不管如何延长时间,毁损灶达到一定范围后就不再扩大,再增加温度,对毁损灶的影响亦不大.结论ASA-601TS型温控热凝射频仪,对兔脑组织毁损灶形成是可靠和安全的.在温度达70℃或75℃,持续60秒以上,可作一直径为6～6.5mm的毁损灶.     

CO_2激光照射兔脑后神经细胞超微结构变化的实验研究

本实验选用30只家兔脑,经CO_2激光照射后,在30天再生修复动态变化过程中,电镜下见到受损伤的神经组织呈现暗型、中问型、明亮型3种神经元形态。提示激光损伤后由于脑缺血和离子浓度发生紊乱,导致神经细胞缺氧、皱缩,密度增高,最终转化为液化性坏死。在损伤组织中,见到有明显的星形细胞增生,周围的正常神经组织也发生反应性胶质增生。     

Volumetric quantification of brain development using MRI

We devised a three-dimensional method for estimation of cerebral development and myelination which measures cerebral volume using MRI. Accuracy of the system was estimated using cadaver brains. The mean percentage error in the calculated volumes compared with the real volumes was 2.33 %, range 0.00–5.33 %. We applied the method to the volume of both cerebral hemispheres (CH), basal ganglia, thalamus and internal capsule (BT), and myelinated white matter (WM) in 44 neurologically normal individuals (4 months to 28 years of age), 13 patients with spastic motor disturbances (2–25 years of age), and 9 patients with athetotic motor disturbances (2–23 years of age). In the neurologically normal cases, the volumes of CH, BT and WM increased with age; the volume of MW more slowly than that of CH. In cases with spastic motor disturbances, the volumes of CH, BT and WM were between –1.4 and 3.5 SD, –1.0 and –3.5 SD, and 0.0 and –5.2 SD respectively, of those of neurologically-normal cases. On the other hand, 7 of the 9 cases with athetotic motor disturbances were within 2 SD of the volume of CH in neurologically normal cases. Our method for direct measurement of cerebral volume based on serial MRI should be useful for the accurate assessment of brain development and quantitative analysis of delayed myelination. Received: 30 November 1995 Accepted: 27 January 1997