CT和MRI三维定位在神经导航立体定向系统中的应用

目的：为神经导航定位系统提供最精确的医学影像资料，提高神经外科手术的质量和成功率。材料和方法：结合医学影像的薄层扫描和三维重建技术，调整CT和MRI导航定位扫描中的各项参数。结果：确定了神经导航立体定向系统的CT和MRI定位扫描步骤及参数，为临床提供了精确的影像资料，共完成25例病例的手术治疗，效果满意。结论：精确的医学影像资料是神经导航定位系统准确性的重要保证。     

Juxtacortical chondromyxoid fibroma: imaging findings in three cases and a review of the literature

Chondromyxoid fibroma is a rare bone neoplasm characterized by chondral, myxoid and fibrous differentiation. Uncommon locations include the bone surface. Roentgenography, MRI and ultrasound can suggest the diagnosis. However, diagnosis of chondromyxoid fibroma is rarely made prior to biopsy. We present the radiologic and pathologic findings in three patients with this tumor and a review of the literature.     

Diagnosis of adsorption on solid electrodes using semi-integral voltammetry: A generalization via asymptotic analysis

A diagnosis of adsorption on solid electrodes using semi-integral voltammetry, initially proposed by Bowling and McCreery for a reversible charge transfer without coupled chemical reactions, is re-examined in the general case. Towards this aim, we show that an asymptotic analysis of the semi-integrated (or convolved) voltammograms is sufficient to conclude. A straightforward approach is designed which enables an examination of all previous hypotheses available in the literature: reversible or irreversible charge transfer, involvement of adsorbed reactants and/or products of the charge transfer or pure diffusion, and occurrence of coupled chemical reactions. We apply our asymptotic approach to all these cases, and show that the adsorption hypothesis is the only one to yield peak-shaped semi-integrated voltammograms, while monotonically increasing S-shaped semi-integrated voltammograms are obtained in the pure diffusion approximation. We find that the exclusive assumption of adsorption versus pure diffusion is sufficient to lead to discriminating behaviour, as the consideration of all other hypothesis (reversibility of the charge transfer, coupled chemical reactions) does not alter the conclusions. Thus, a hierarchy in the various hypotheses exists, which alludes to the systematic use of semi-integral voltammetry as a practical route to the diagnosis of the involvement of adsorption phenomena in electrochemical processes. Possible restrictions to this proposal are examined, as well as the way in which they may be overcome.     

Monte Carlo simulation of spontaneous miniature excitatory postsynaptic currents in rat hippocampal synapse in the presence and absence of desensitization

 Using the Monte Carlo method, spontaneous fast excitatory postsynaptic currents (mEPSCs) at a hippocampal synapse were simulated by releasing 150–20,000 glutamate molecules from a point source centred 15 nm above a rectangular grid of 14 × 14 α-amino-3-hydroxy-methyl-isoxazole (AMPA) receptors and assuming the channel kinetics to be as reported by Jonas et al. [J Physiol (Lond) 472:615; 1993]. The relationship between the amplitudes of mEPSCs and their time constants of decay is positive, but not pronounced in physiological conditions (except when the number of molecules released is very high). It increases as desensitization is reduced and becomes highly pronounced when it is eliminated. mEPSCs are prolonged with repeated opening of AMPA channels due to enhancement of two concentration-dependent processes: (1) binding of glutamate molecules by AMPA receptors, and (2) occupancy of both activatable bound states. In contrast, the time constant of decay of the patch currents evoked by a short glutamate pulse is independent of glutamate concentration and current amplitude in control conditions, and only moderately concentration dependent in the absence of desensitization. The fast application protocol thus fails to reproduce synaptic currents reliably when there is repeated binding of glutamate molecules to AMPA receptors. During an mEPSC, the occupancy of desensitized states increases rapidly and it strongly depends on the number of glutamate molecules released. Desensitization reaches its maximum after an mEPSC decays to very low levels, and recovers very slowly (from tens to hundreds of milliseconds), and in a concentration-dependent manner. In conclusion, under physiological conditions the desensitization of AMPA receptors plays a major role in shaping the time course of mEPSCs by minimizing the repeated opening of AMPA channels. Received: 17 April 1997 / Received: after revision: 11 August 1997 / Accepted: 1 September 1997     

FTY720 Pretreatment Reduces Warm Hepatic Ischemia Reperfusion Injury Through Inhibition of T-Lymphocyte Infiltration

Ischemia and reperfusion (IR) injury remains a significant problem in clinical liver transplantation. We investigated the effects of lymphocyte depletion with FTY720 in models of warm hepatic IR. Using 60-min partial warm hepatic IR, three groups of rats were studied: Sham--laparotomy alone; Control--water p.o. x 3 d before ischemia; Treatment--FTY720 p.o. x 3 d before ischemia. Animals were sacrificed for analysis at 6 h and 24 h post reperfusion. The effect of FTY720 pretreatment on survival was also studied using 150 min total hepatic IR with portojugular shunt. FTY720 treatment significantly reduced serum glutamic pyruvic transaminase and peripheral blood lymphocytes compared to controls at 6h and 24h (p < 0.0005). Histological grade was significantly improved in treated livers vs. controls (p < 0.05). CD3 immunocytochemical analysis revealed a significant reduction in T-cell infiltration in FTY720-treated livers (p < 0.0002). No difference in tissue myeloperoxidase levels was observed. Seven-day survival was significantly improved in treated rats vs. controls following total hepatic ischemia (p < 0.05). In conclusion, FTY720 ameliorates the biochemical and histological manifestations of hepatic IR by preventing T-lymphocyte infiltration and prolongs survival following a more severe ischemic insult. Myeloperoxidase data suggest this mechanism is independent of neutrophil activation. These results indicate that T lymphocytes are pivotal mediators in hepatic IR and may have important implications in liver transplantation.     

COX-2和凋亡抑制蛋白在老年胃癌患者原发灶与转移淋巴结中的表达差异

目的:探讨老年胃癌患者原发灶及淋巴结转移灶中环氧合酶2(COX-2)与凋亡抑制蛋白p53,survivin,Bcl-2表达的关系及其意义。方法:用免疫组化染色法检测33例伴淋巴结转移的老年胃癌患者(≥60岁)手术标本中COX-2,p53,survivin和Bcl-2的表达情况,同法检测32例对照组(<60岁)胃癌原发灶、转移灶中上述4种蛋白的表达,比较两组之间、淋巴结转移灶与原发灶之间的表达差异,并进行相关分析。结果:老年组转移灶中Bcl-2的表达高于原发灶(P<0.05),COX-2,p53和survivin表达在两种病灶组织间无统计学差异(均P>0.05),p53及Bcl-2表达在原发灶、转移灶间存在正相关(r分别为0.5470及0.4969,均P<0.01)。老年患者原发灶中COX-2与survivin,COX-2与Bcl-2之间呈正相关(r=0.5053;r=0.5741,均P<0.01),转移灶中survivin与Bcl-2表达呈负相关(r=-0.5414,P<0.01)。老年组原发灶COX-2,survivin和Bcl-2表达明显高于对照组(均P<0.05),而转移灶仅COX-2的表达高于对照组(P<0.05)。结论:大于60岁老年胃癌患者,原发灶与淋巴结转移灶的COX-2的表达与60岁以下的胃癌患者存在差异,这可能导致老年患者凋亡抑制途径与其他年龄患者不同。     

216份冠状动脉支架置入术手术编码错误分析及探讨

目的 对冠状动脉支架置入术手术编码中存在的问题进行分析探讨.方法 收集行冠脉支架置入术的出院病案共216份,按照ICD-9-CM-3编码原则,分析主要手术填写及编码情况,对其中出现的错误进行汇总分析.结果 医师填写该类主要手术时共存在错误69份,总错误率为31.9％.编码员存在的最主要的问题为遗漏血管手术数量,占53.2％.结论 加强对心内科医师有关冠脉支架置入术ICD-9-CM3知识的专项培训,提高编码员自身业务水平及编码能力,双方共同努力才能减少冠状动脉支架置入术编码的错误率.     

现代医院实施感动服务的探讨

探讨在现代医院引入感动服务的必要性,并对实施医院感动服务的措施进行研究,促进医院品质全面提升