Cytomegalovirus (CMV) infections in patients receiving CMV-IgG-hyperimmunoglobulin prophylaxis after bone-marrow transplantation

Summary Conditioning therapy with aggressive chemotherapy and irradiation induces a state of transient combined immunodeficiency in bonemarrow transplant recipients. This promotes the occurrence of severe cytomegalovirus (CMV) infections, the most frequent lethal complication after bone-marrow transplantation (BMT) at present.Forty-four BMT recipients received CMV-IgG-hyperimmunoglobulin for CMV prophylaxis intravenously. The efficacy of this prophylaxis and possible risk factors for the occurrence of CMV-induced interstitial pneumonia (IP) were analyzed. Risk factors for the promotion of a CMV-IP were: additional immunosuppressive therapy after BMT, CMV-positive serostatus of the recipient, CMV-seropositive granulocyte transfusion, CMV infection immediately prior to BMT, and HLA-haploidentical BMT. In this study the incidence of graftversus-host disease was low and was not associated with the incidence of CMV infections. The use of T-cell-depleted grafts did not result in increased CMV infections or IP and may possibly have improved the immunological reconstitution.Abbreviations BMT Bone-marrow transplantation - CMV Cytomegalovirus - CMV-IG CMV-IgG-hyperimmunoglobulin - GvHD Graft-versus-host disease - IP Interstitial pneumonia - IS Immunosuppressive therapy     

激光扫描共聚焦显微镜在肿瘤研究中的应用

激光扫描共聚焦显微镜是近年来出现的一种新的分子细胞生物学分析仪器,已经广泛应用于生物医学研究的许多领域.简介其基本功能和特点.并从肿瘤组织细胞蛋白的定位和定量、肿瘤细胞亚细胞结构观察、肿瘤受体研究、肿瘤药物分布和肿瘤多耐药机制等角度.综述了近年来激光扫描共聚焦显微镜在肿瘤研究中应用的进展.     

低能量激光血管内照射治疗脑梗死的临床观察

目的:探讨采用低能量半导体激光血管内照射疗法(intravascular laser irradiation on blood,ILIB)治疗脑梗死的效果及机制.方法:随机选取80例脑梗死患者分为治疗组与对照组,两组各40例,两组患者接受同样的药物治疗,治疗组在上述治疗的基础上,于发病1 d～3 d内,加用半导体激光血管内照射治疗.采用国产半导体激光治疗仪,波长650nm,功率1.5mW～2.0mW.患者平卧,消毒后用静脉留置针穿刺上肢正中静脉或贵要静脉,成功后留置外套管,通过管脑导入激光剂,开启半导体激光治疗仪进行照射治疗.结果:治疗组有效率92.5%,与对照组差异有显著性意义(p＜0.01),治疗组患者临床症状和体征治疗后明显改善.结论:该疗法有调节脂质代谢,改善血液流变学性质,恢复神经传导功能等功效,进而提高脑梗死的治疗效果.     

Simulation of laser tomoscopy in a heterogeneous biological medium

A Monte Carlo model has been developed to study the propagation of an ultrashort light pulse through a heterogeneous thick biological specimen. A circular blood vessel is moved within a tissular slab to simulate biological specimen scanning using a picosecond laser source and a collimated ultrafast multichannel opticl shutter. Features of the transmitted light are computed for each position of the blood vessel. The computer program gives an account of the transmitted photons, the flight time which does not exceed straightforward crossing time plus time gate of known duration. A small blood vessel (radius R=2 mm) placed in a 40 mm thick slab is easily located when a time gate of 10 ps duration is employed. Such a time gate also allows the detection of a middle-sized vessel (R=4 mm) embedded in a thicker sample (80 mm). The contrast computed for the transmittance profile is greatly improved when a time gate is used. In addition, shifting of the blood vessel towards the unilluminated side of the sample decreases the contrast. We demonstrate that the time selection process may provide a substantial improvement to the laser tomoscopy technique when used for imaging biological media.     

Investigation and improved performance of optical fibre probes in laser Doppler blood flow measurement

Laser Doppler flowmetry with optical-fibre beam transmission is a sensitive fast and convenient method of measuring tissue blood flow. However, its sensitivity can also be a problem because of movement artefacts. This study applies some basic considerations of fibre optics and Rayleigh light scattering to the field of laser Doppler blood flow meters. Practical suggestions are given by which movement arterfacts can be reduced by choice of optical fibres, attention to probe geometry, cladding the fibres to reduce their movements and in the method of application. Experiments which test the normalisation circuitry of laser Doppler instruments are described and the effects of movement artefacts on the interpretation of the pulsatile component of laser Doppler records are also discussed. Probe and fibre line movements cause high-frequency intensity fluctuations due to speckle movement. The intensity fluctuations produce an apparent Doppler shift much greater than the Doppler shift produced by the relative movements of probe and tissue. It has been found that it is important to ensure that the fields of view of the illuminating and detecting fibres do not overlap at the skin surface and that probe contact with the skin surface should be maintained.     

Laser tomography of heterogeneous scattering media using spatial and temporal resolution

Time-resolved tomography is performed in transillumination by using 527 nm picosecond pulses from a passively mode-locked doubled Nd/glass laser and a streak camera to select photons according to their flight time. This work reports on the increase in contrast of a time-resolved profile of a 2 mm radius opaque object embedded in a scattering medium, constituted of diluted milk in a 30 mm thick cell. For spatial analysis, the emerging photons are detected through a 6 mm slit at the outlet face of the cell. Transmission profiles obtained as a function of time show that the contrast is enhanced for the shortest flight times, while the ‘shadow’ of the object is no longer detected after about 100 ps. Moreover, improvements in contrast are studied for different configurations of the model, to analyse separately the role of collimated and scattered photons. It is expected that such a tomographic method based on time-resolved absorption could be applied to imaging for more complex biological structures in the red and near-infra-red range.     

硫化氢对体外大鼠肝星状细胞内Ca2+浓度变化及细胞增殖的影响

目的 研究硫化氢(H₂ S)对大鼠肝星状细胞-T6(HSC-T6) Ca²⁺浓度、细胞增殖的影响及其机制。 方法 活化HSC-T6用含10%小牛血清DMEM培养液制备为1×10⁵个肝星状细胞(HSC)悬液。钙离子荧光探针Fluo-3/AM负载细胞后，在不同刺激条件下，利用激光扫描共焦显微镜动态扫描HSC-T6细胞内Ca²⁺荧光强度（FI）变化，FI表示细胞内Ca²⁺浓度。四唑盐比色法，观察不同浓度H₂S供体——NaSH对HSC-T6细胞增殖的影响。 结果 低浓度H₂S（100μmol/L）明显降低HSC-T6细胞内Ca²⁺浓度（P<0.05)，而细胞增殖增加（增殖率为116%）；K_ATP通道阻断剂——格列本脲可阻断H2S的作用。高浓度H₂S（1mmol/L）刺激HSC-T6细胞内Ca₂₊浓度增加，但细胞增殖无明显变化(P＞0.05)。 结论 低浓度H₂S通过激活HSC-T6细胞K_ATP通道降低细胞内Ca²⁺浓度，可能通过调节细胞氧化应激促进细胞增殖；高浓度H2S刺激HSC-T6细胞内Ca₂₊浓度增加。提示H₂S在肝硬化门脉高压症的发生机制中具有双重作用。     

肱骨头两维平面激光投影测量

本文报道用激光对100例成人肱骨头进行两维平面测量,即正位、侧位、左、右45°斜位肱骨头的半径、关节面高度、张角及表面面积等。其结果为:1.肱骨头关节面的张角平均为144.48±11.93°。2.肱骨头半径及高度分别为2.15±0.16 cm、1.56±0.24 cm。肱骨头关节面高度占近似球体直径的36.05％。3.肱骨头关节面的表面积为21.02±4.03 cm~2。4.激光测量比接触测量客观、准确,可以重复并易取得统一标准,为骨胳测量提供一种较好方法。根据所测肱骨头半径与关节面张角,即能绘出肱骨头关节面的图形,计算出关节面曲率。本文对设计、制造肱骨头提供了国人数据,也可为肱骨头生物力学的研究提供参考。     

利用磁共振成像实现肿瘤热疗中实时无创测温的方法

肿瘤热疗特别是高强度聚焦超声（HIFU）技术，已成为一种重要且非常具有前景的肿瘤治疗方法，温度是直接决定热疗效果的重要参数，实时准确的进行深部无创测温是目前制约肿瘤热疗进一步发展的一项关键技术。近来利用磁共振成像（MRI）进行无创测温，正受到越来越多的研究者的重视。本文简述了MRI无创测温的三种方法，比较了不同测温原理的特点和适用条件，报道了已有研究发展状况，并介绍了尚待解决的问题。