无国界医生在救援中备灾的重要性

无国界医生致力于应对天灾和战祸所引起的人道医疗危机。灾后实时爆发的人道医疗危机包括急性的外科创伤问题和基础医疗系统的破坏导致疫症发生。本文介绍了无国界医生的救援经验以及专业的备灾体系。     

左旋布比卡因复合舒芬太尼或芬太尼在分娩硬膜外自控镇痛的应用

目的探讨左旋布比卡因复合舒芬太尼硬膜外自控镇痛（PCEA）用于分娩镇痛的临床效果及安全性。方法随机选择120例美国标准协会（ASA）I-Ⅱ级初产妇，随机分为舒芬太尼组（A组）、芬太尼组（B组）、无镇痛组（C组），每组40例。A组和B组采用PCEA，C组不给予镇痛药物。观察各组不同时段视觉模拟评分（VAS）和不良反应的发生，同时记录3组产程时间、分娩方式、缩宫使用情况、产后出血量、新生儿Apgar评分。结果A、B2组和C组在PCEA20、60min及宫口开全时VAS差异有统计学意义（P〈0.05）；PCEA5min，A、B2组VAS差异有统计学意义（P〈0.05），2组Bromage评分、不良反应差异无统计学意义（P〉0.05）。3组产程时间、分娩方式、产后出血量、新生儿Apgar评分比较差异均无统计学意义（P〉0.05）。结论左旋布比卡因复合舒芬太尼或芬太尼用于分娩镇痛安全有效，对母婴无明显不良影响。     

MicroRNAs及其在泌尿系肿瘤的研究进展

microRNAs（miRNAs）是一类分布十分广泛的内源性非编码RNA,在动物、植物、病毒中广泛存在。miRNAs与肿瘤的发生发展预后有关,并在肿瘤的增殖、分化及调亡等方面有重要的作用。结合最近相关文献,本文就miRNAs与泌尿系肿瘤方面的进展作简要概述。     

同一经穴左右主治不同初探

根据有关文献记载,从穴位与内部脏器相应的认识出发,列举古今临床上区别应用的实例,及近代应用穴位诊断疾病方面的资料,提出位于胸腹腰背部的左右同名经穴由于相应内部脏器不同,主治病症也不完全相同,因而临床应区别使用的见解。     

质疑Frank—Starling心脏定律

心脏收缩释放的能量（作功）是心肌纤维长度（心室舒张末期容积，EDV）的函数，即Frank—Star一1ing（FS）心脏作功定律，被誉为心脏生理学中的“经典”理论。对此，笔者从各种不同角度进行了探讨：首先分析了Frank伸展离体心肌和Starling及其同事使用心肺制备做的实验与动物生理实际的差异，以及人们在实验中观测到的增加心肌前负荷引起收缩力增强的现象（FS现象），认为：①在正常生理条件下的动物体内，来自心脏以外的、如同心肺制备中那样人工控制心室充盈压力升高、引起EDV增加的那种血液的重力动力是不存在的。②另一方面，人为地增加前负荷，那是改变了心肌收缩时的外环境条件。③由此而激发出的FS现象，是心脏适应其外环境条件变化所作出的反应。④此种心肌收缩力增强的反应，需通过心肌细胞内部与收缩过程发生有关的心肌兴奋一收缩和化学一力学偶联等一系列生化机制（不恒定因素）方能得以实现。⑤根据他们实验中观测到的FS现象，在逻辑上不能得出前负荷这一心肌收缩时的外环境条件变化调控其作功的推论。换言之，所有的在实验中被激发出来的FS现象，都不足以成为支持FS心脏定律的证据。然后，引用国内外公认的计算心脏每搏射血作功（w）的生物物理学公式“w=P×（EDV—ESV）”，证明了w和EDV之间没有函数关系。根据心脏作功的医用物理学和生物数学的基本原理，笔者认为Frank—Starling心脏定律表达的不是心脏作功的规律。     

弥漫性大B细胞淋巴瘤中CD40L的表达及意义

目的探讨弥漫性大B细胞淋巴瘤（DLBCL）组织中CD40L表达与DLBCL预后间的关系及意义。方法免疫组织化学法检测27例弥漫性大B细胞淋巴瘤、20例淋巴结反应性增生组织中CD40L的表达。结果（1）DLBCL中CD40L过度阳性率（25．93％）显著低于淋巴结反应性增生（63．64％），P〈0．05。（2）CD40L在Ⅲ、Ⅳ期DLBCL过度阳性率（14．29％）低于Ⅰ、Ⅱ期（38．46％），P〈0．05。CD40L过度阳性率在有结外浸润DLBCL（11．76％）低于无有结外浸润DLBCL（40％），P〈0．05。（3）DLBCL患者CD40L的过度阳性率与远处转移、临床分期均显著相关，P〈0．05。结论（1）CD40L过度阳性率与结外器官浸润及临床分期密切相关，其可能作为判断DLBCL侵袭性及预后的指标。（2）DLBCL中CD40L表达的减少可能是影响其发病的因素之一。     

Mdm2、Bc1-2、AR在良性脑膜瘤中表达的关系

目的研究凋亡相关蛋白mdm2、bcl-2和AR（雄激素受体）之间的关系，为脑膜瘤的性激素对抗治疗提供一些新信息。方法从华西医院病理科获得04年1月-07年12月病理诊断明确的脑膜瘤共394例，计算机随机抽样60例，其中良性脑膜瘤（WH0I）41例，用LsAB法做免疫组化染色，检测mdm2、bcl-2、AR的表达。结果在良性脑膜瘤中mdm2、bcl-2、AR的表达率分别为67％、62％、33％，三者之间没有相关关系。结论（1）是否能够作为抗性激素治疗疗效的筛选和／或预测指标，bcl-2比mdm2更有潜在价值。（2）AR在脑膜瘤中的促进生长作用的相对独立性，提示AR可以作为脑膜瘤对抗激素治疗的新靶点进一步研究。     

A 23-pS Ca2+-activated K+ channel in MCF-7 human breast carcinoma cells: an apparent correlation of channel incidence with the rate of cell proliferation

In studies on the apical membranes of cultured MCF-7 human breast carcinoma cells, we found two conspicuous K⁺ channel types with conductances of 23 and 70 pS, respectively. Of these, the 23-pS K⁺ channel was most conspicuous. In cell-attached patches with KCl in the pipette, it had a linear current/voltage (I/V) relation and was activated by depolarisation and in excised insideout patches it was highly selective for K⁺ over Na⁺ (permeability ratio of Na⁺ to K⁺, P _Na/P _K=0.02). Rubidium (Rb⁺) had a similar permeability to K⁺, although it was only conducted at 20% of the rate of K⁺, and cesium (Cs⁺) had a permeability less than 30% that of K⁺ and was not conducted at all. Both Cs⁺ and Rb⁺ acted as partial blockers when applied internally but the channel was not blocked by external tetraethylammonium (TEA, 10 mmol/l), quinidine (200 mol/l) or apamin (50 nmol/l). It was activated by Ca^{2 +} in the range 10^–7–10^–6 mol/l. In cell-attached patches at a pipette potential of 0 mV, the open-time histogram was described by a single exponential (time constant 1.6 ms) and the closed-time histogram by two exponentials (time constants 0.5 and 1.5 ms). The incidence of the 23-pS but not the 70-pS channel depended on the rate of cell proliferation. Thus, in studies on cell-attached patches from cells in the exponential growth phase, the 23-pS channel was observed in 78% of patches. However, when the proliferation rate was decreased, whether as a result of allowing the monolayer to reach confluence, or of cell treatment with an anti-oestrogen (tamoxifen, 10 mol/l), or a phorbol ester [phorbol 12-myristate 13-acetate (TPA), 2.6 nmol/l], the channel incidence was reduced to 42%, 60% and 42%, respectively. The activity of the 23-pS channel is not obligatory for cell division, however, since the rate of cell proliferation remained the same in MCF-7 cultures in which the channel was not expressed.     

Activation kinetics of Glutamate receptor channels from wild-type Drosophila muscle

Outside-out patches from wild-type Drosophila larval muscle were exposed briefly to L-Glutamate (Glu) using a piezo-driven application system. Glu in concentrations of 0.1 to 30 mM was applied and the responses to repeated applications of a given concentration were averaged. The peak current, î, and the current rise time, t_r, from 0.1 î to 0.9 î were determined from the averages. Half-maximum activation of the channels was reached with ≈ 2 mM Glu. î increased proportional to the power n = 3.5 to n = 5.8 (average of four experiments, n = 4.4) for Glu concentrations between 0.3 and 0.5 mM. t_r increased from ≈ 0.2 ms at 10 mM Glu to a value of ≈ 3.5 ms at 0.2 mM Glu. A linear reaction scheme with five binding steps preceding the channel-opening conformational change is proposed as the kinetic mechanism of channel activation and investigated in computer simulations. A set of rate constants assuming the same affinity for each binding site is found to describe the data better than one assuming positive cooperativity. The results are very similar to those for Glu-gated channels of crayfish and locust muscle, which is evidence for a common kinetic mechanism of these channels.     

成人骨髓间充质干细胞对造血干细胞体外增殖的影响

目的研究骨髓间充质干细胞（MSC）对脐带血（CB）CD34^＋细胞体外增殖和造血重建能力的影响。方法取人骨髓单个核细胞贴壁培养．梭形细胞完全融合后传代，用流式细胞仪检测免疫表型；将CBCD34^＋细胞接种到MSC或其他培养液中．比较不同培养条件对造血干细胞扩增能力、集落形成能力及黏附分子表达的影响。结果在加入IL-3的培养体系中．在MSC和细胞因子作用下，CD34^＋细胞扩增7d和14d后，有核细胞（NC）、CD34^＋细胞和CDl33^＋细胞数，实验组均显著多于对照组。CD34＋细胞在未加入IL-3的培养体系中培养8d后，实验组NC、CD34^＋细胞、CD34^＋CD38-细胞和造血祖细胞集落扩增倍数均显著高于对照组。扩增后CD34^＋细胞的ALCAM、VLA-α4、VLA-α5、VLA-β1、HCAM、PECAM和LFA-1表达较扩增前无显著变化。结论MSC可为造血干细胞（HSC）体外扩增提供适宜的微环境，有助于CD34^＋细胞体外增殖并抑制HSC分化，保持其造血重建潜能和归巢能力。