非程控降温,—80℃冻存自体外周血干细胞的研究

目的：观察非程控降温、－80℃冻存的方法对自体外周血十细胞（APBSC）的保存效果。方法：以6％羟乙基淀粉（HES）、5％二甲基亚砜（DMSO）及4％人血白蛋白（ALB）的混合物为冷冻防护剂，将APBSC直接置于－80℃下保存，冻存前反复苏后测定APBSC的CFU－GM、BFU－E；观察移植后造血功能重建情况。结果：13例患者白细胞在十3～＋7天下降至（0．0～0．1）×10／L，白细胞（0．0～0．2）×109／L持续时间3～6天，于＋9～＋11天恢复至1．0X109／L以上．中性粒细胞绝对值（ANC）于＋9～＋11天达到0．5X109／L。血小板在＋3～＋7天下降至（2．0～21）×109／L，于＋8～＋15天恢复至20×109／L以上。CFU－GM、BFU－E回大率分别为76．5％、78．4％。结论：非程控降温、－80℃冻存是一简便、经济、有效的自体外周血于细胞保存方法。     

Carcinogenicity of zeolite-phillipsite

Phillipsite dust was intrapleurally administered to random-bred rats by 20 mg in 0.5 ml of saline three times with an interval of a month. Higher incidence of hemoblastoses has been experimentally found in exposed animals compared to the control ones. One rat developed pleural mesothelioma, two rats lung adenocarcinoma. It was concluded that phillipsite has weak carcinogenic activity.     

Isolation of pathogenic bacteria from hospital staff apparel in Nigeria

A survey of bacteria contamination of hospital staff apparel in use in Anambra State, Nigeria, was carried out to determine the extent of contamination by clinically important bacteria. Of a total of 125 swab samples of hospital staff apparel, 72 (58%) showed bacterial contamination including 32 (70%) of 46 samples from hand gloves, 28 of 45 (62%) samples from protective gowns, and 12 of 34 (35%) samples from face-shields. The potentially pathogenic bacteria isolated were Salmonella spp, Proteus vulgaris, Shigella dysenteriae, Pseudomonas aeruginosa and Staphylococcus aureus. The isolation of clinically important bacteria from the apparel suggests the need for improved infection control measures.     

大鼠急性肺栓塞后SMP-30表达下降及其对细胞凋亡的影响

目的：研究大鼠急性肺栓塞模型肺组织中衰老标记蛋白质30(SMP-30)的表达变化及其对Fas诱导的细胞凋亡的影响。方法:建立大鼠急性肺栓塞模型，分别在急性肺栓塞后1、8、24和48 h进行支气管肺泡灌洗，然后开胸取出肺组织。常规提取肺组织的总RNA和总蛋白，以正常组为对照，采取半定量RT-PCR的方法研究SMP-30在mRNA水平表达的变化；采用Western blotting方法进一步验证SMP-30在蛋白水平表达的变化；采用免疫组织化学方法检测大鼠肺组织中SMP-30以及肺泡巨噬细胞中IL-8在肺栓塞前后表达的变化及其组织分布情况；采用TUNEL法研究急性肺栓塞后组织细胞的凋亡情况；最后采用ELISA法检测急性肺栓塞后肺泡灌洗液中sFasL的浓度变化。结果:在大鼠急性肺栓塞后的不同时点，SMP-30的mRNA水平和蛋白水平均逐渐降低，在24和48 h下降最为明显。免疫组化研究表明SMP-30主要分布在支气管黏膜上皮细胞和肺泡上皮细胞，急性肺栓塞后SMP-30在上述细胞内的表达均明显降低。TUNEL染色发现随着SMP-30表达的降低，肺组织内出现明显的细胞凋亡现象，同时肺泡灌洗液中sFasL的浓度升高，肺泡巨噬细胞内IL-8的表达也明显升高。结论:大鼠急性肺栓塞后肺组织内SMP-30的表达明显降低，可能促进Fas－FasL细胞凋亡系统的活化。     

The hygienic assessment of atmospheric pollution by xylene isomers

The biological action of xylol isomers as ambient air pollutants was investigated. The maximum single allowable concentrations of orthoxylol (0.3 mg/m3), methaxylol (0.24 mg/m3), papaxylol (0.27 mg/m3) were determined by measuring the odour thresholds of the substances in 122 volunteers. The average daily allowable concentrations of the xylol isomers were found to be 0.4, 0.16, and 0.96 mg/m3, respectively.     

Activity-dependent reconfiguration of the effective dendritic field of motoneurons

A neuron in vivo receives a continuous bombardment of synaptic inputs that modify the integrative properties of dendritic arborizations by changing the specific membrane resistance (R(m)). To address the mechanisms by which the synaptic background activity transforms the charge transfer effectiveness (T(x)) of a dendritic arborization, the authors simulated a neuron at rest and a highly excited neuron. After in vivo identification of the motoneurons recorded and stained intracellularly, the motoneuron arborizations were reconstructed at high spatial resolution. The neuronal model was constrained by the geometric data describing the numerized arborization. The electrotonic structure and T(x) were computed under different R(m) values to mimic a highly excited neuron (1 kOhm x cm(2)) and a neuron at rest (100 kOhm x cm(2)). The authors found that the shape and the size of the effective dendritic fields varied in the function of R(m). In the highly excited neuron, the effective dendritic field was reduced spatially by switching off most of the distal dendritic branches, which were disconnected functionally from the somata. At rest, the entire dendritic field was highly efficient in transferring current to the somata, but there was a lack of spatial discrimination. Because the large motoneurons are more sensitive to variations in the upper range of R(m), they switch off their distal dendrites before the small motoneurons. Thus, the same anatomic structure that shrinks or expands according to the background synaptic activity can select the types of its synaptic inputs. The results of this study demonstrate that these reconfigurations of the effective dendritic field of the motoneurons are activity-dependent and geometry-dependent.