[课件]微透析技术PPT

低 低
低 (10- 5~10- 3mol/L) 高
Intracerebral microdialysis during deep stimulation surgery
1.Background
This report describes the use of microdialysis in conjunction with deep stimulation (DBS) surgery to assess extracellular levels of neurotransmitters within the human basal ganglia(BG). Electrical stimulation of the subthalamic nucleus(STN) is an efficacious treatment for advanced Parkinson’s disease, yet the mechanisms ofSTN DBS remain poorly understood. Measurement of neurotransmitter levels within the BG may provide insight into mechanisms of DBS, but such an approach presents technical challenges.
2. Methods
Five patients undergoing DBS surgery for advanced participated in our study.Four of the patients were male and one patient was female. The mean age at the time of surgery was 57 years, and the mean length of diagnosis was 8.7 years. Individual patient characteristics are reported in Table 1.
2.1. Microdialysis baseline studies
Prior to the start of dialysis, this apparatus was perfused with a mock CSF solution for 5 min at 2.0 μL/min in order to discard the dead volume.The location of was confirmed using intraoperative microrecordings per routine. The standard DBS guide cannula was then replaced with a custom designed microdialysis guide cannula (Fig. 1), and the microdialysis probe was inserted so that its membrane was located in the (Fig. 2).
Fig 1
Fig 2
The microdialysis guide cannula was a modified 18gauge epidural needle. The needle was shortened such that the length from the top of the cuff to the tip of the needle was 60 mm. A polymethyl ring with outside diameter of 8 mm was added above the existing cuff. With these modifications, the needle could be mounted on the DBS microdrive in place of the standard guide cannula (see Fig. 1B). The catheter was perfused at a rate of 2.0 μL/min, and samples were collected every 15 min for 60 min in patients 1 and 2 (Fig. 3).
脑微透析技术
脑微透析技术是一种在体或离体脑化学采样
技术 ,其原理是脑细胞外液中可溶性分子可通过
一种半透膜管的微小径孔顺浓度梯度扩散。半
透膜管连接在经立体定位技术植入大脑特定部 位的探针上 ,探针则与灌注泵相连 ,向管内灌注 与管外组织间液近似的人工脑脊液或其他液体。
脑微透析探针
典型的同心圆型微透析探针包含连接有进 液和出液两根管子和一个圆柱状的透析膜 。
1 2 3 4
5
61
10
675
All patients were asked to discontinue their antiparkinsonian medications at midnight prior to the morning of surgery. DBS surgery is typically performed in awake, conscious patients, although local analgesia is provided at the surgical site.
微透析技术
微透析(Microdialysis)技术
一种将灌流取样和透析技术结合起来并逐渐 完善的一种从生物活体内进行动态微量生化取样 的新技术。具有活体连续取样、动态观察、定量 分析、采样量小、组织损伤轻等特点。
微透析系统装置
主要由微量泵、微透析探头、收集器、连 接管及配套设备组成。 将一种具有透析作用的微细探针置于采样的 生物组织内，利用一部非常精细的注射泵，推 送溶液至探针处，以达到与组织内欲取出测量 的低分子量物质，进行透析交换，再将透析液 做进一步的分析。
脑微透析与其他技术的ห้องสมุดไป่ตู้较
项目 脑微透析 PET MRS
分析样品
脑损伤性 取样部位
无
有 组织的细胞外液
正电子放射同位 素
无（但具有放射 性） 组织
核素
无 组织
操作复杂性
代谢产物
低
可检测
高
不可检测
高
可检测
时间分辨率 空间分辨率
灵敏度 成本
高 高
高 (10- 9~10- 3mol/L) 低
高 中
高 ( 10- 12mol/L ) 高
Table 1 Patient characteristics
Patient Age (years) 48 55 61 59 Length of diagnosis (years) 3 8 10 10 L-dopa equivalent medication before surgery (mg/day) 1050 625 500 625