Parvalbumin 3 is an Abundant Ca2+ Buffer in Hair Cells

Ca2+ signaling serves distinct purposes in different parts of a hair cell. The Ca2+ concentration in stereocilia regulates adaptation and, through rapid transduction-channel reclosure, underlies amplification of mechanical signals. In presynaptic active zones, Ca2+ mediates the exocytotic release of afferent neurotransmitter. At efferent synapses, Ca2+ activates the K+ channels that dominate the inhibitory postsynaptic potential. A copious supply of diffusible protein buffer isolates the three signals by restricting the spread of free Ca2+ and limiting the duration of its action. Using cDNA subtraction and a gene expression assay based on in situ hybridization, we detected abundant expression of mRNAs encoding the Ca2+ buffer parvalbumin 3 in bullfrog saccular and chicken cochlear hair cells. We cloned cDNAs encoding this protein from the corresponding inner-ear libraries and raised antisera against recombinant bullfrog parvalbumin 3. Immunohistochemical labeling indicated that parvalbumin 3 is a prominent Ca2+-binding protein in the compact, cylindrical hair cells of the bullfrog's sacculus, and occurs as well in the narrow, peanut-shaped hair cells of that organ. Using quantitative Western blot analysis, we ascertained that the concentration of parvalbumin 3 in saccular hair cells is approximately 3 mM. Parvalbumin 3 is therefore a significant mobile Ca2+ buffer, and perhaps the dominant buffer, in many types of hair cell. Moreover, parvalbumin 3 provides an early marker for developing hair cells in the frog, chicken, and zebrafish.     

直肠癌患者手术前后凝血状态变化的研究

目的：通过研究直肠癌患者凝血与纤溶系统的变化，观察其与手术切除与否、淋巴结转移、细胞分化程度等的关系。方法：选取直肠癌患者58例，于术前及术后两周检测PAGT、PT、APTT、TFPI、D－二聚体、t-PA:a等指标；同期52例非肿瘤病人作为对照组。结果：直肠癌患者较对照组血小板聚集增强（P＜0．05），凝血酶原时间、活化部分凝血活酶时间明显缩短，组织因子途径抑制物降低（P＜0．05），D－二聚体和t-PA:a显著升高（P＜0．01），存在淋巴结转移和低分化腺癌者尤为明显（P＜0．05或P＜0．01），手术切除后有所改善。结论：直肠癌患者处于高凝和纤溶亢进状态，在淋巴结转移和癌细胞分化差的病人中尤为明显；应用抗凝和抗纤溶药物可能对直肠癌的预防有一定作用。     

小包装全氟丙烷气体动力学实验研究

为检验塑料小包装全氟丙烷气体（C3F8）在不同包装和储存方法时浓度变化，将装有5～7mlC3F8的聚氯乙烯小袋，根据不同储藏温度和外包装方法随机分成四组：（1）22℃聚乙烯外包装，（2）36℃聚乙烯外包装，（3）22℃铝箔真空外包装，（4）-29℃聚乙烯外包装；每一组C3F8小袋气体存放一定时间后，应用气相色谱分析方法进行浓度测量。结果：第3组C3F8浓度最高和稳定，第2组浓度随放置时间降低最明显，第4组是临床应用气体的储藏和包装方法，其30天样本浓度和第3组相等，但放置一年时浓度降低。结果显示：塑料小包装C3F8予以铝箔真空外包装是一种可行的方法，利于C3F8运输和普及；聚乙烯外包装的C3F8，应放在-29℃保存，时间不超过一年。     

Effect of Ginkgo biloba on fluidity of blood and peripheral microcirculation in volunteers

In a randomized placebo controlled single-blind cross-over study of n = 10 apparently healthy subjects the influence of Ginkgo biloba (Kaveri) on blood fluidity and cutaneous microcirculation was studied. Microcirculation was measured before and every 30 min for 4 h after administration of Ginkgo biloba; fluidity of blood was determined before and after 1, 2 and 4 h. Significant changes in blood pressure or heart rate were found neither during Ginkgo phase nor placebo phase. Haematocrit, plasma viscosity, erythrocyte rigidity, thrombocyte and leukocyte count as well as thrombocyte aggregation and the number of circulating thrombocyte aggregates were also not influenced by the Ginkgo nor the placebo solution. In contrast a remarkable influence on the erythrocyte aggregation was observed: comparing two samples a significant decrease by 15.6% (p less than 0.001) with regard to the initial value was observed after 2 h. The blood flow in the nail fold capillaries also increased significantly by about 57% (p less than 0.004) 1 h after administration.     

影响去离子水质量的主要因素及排除方法

利用电渗析和离子交换柱除去原水中的各种杂质可得到去离子水．而去离子水的质量直接决定了医用注射液的质量。通过近二年的实际操作．列出了与去离子质量有关的主要因素，并提出一些相应见解。     

Ischemic necrosis of the entire femoral head and rapidly destructive hip disease: potential causative relationship

 Objective. Rapidly destructive hip disease (RDHD) is an uncommon disorder of the hip that has been considered a disease of unknown cause and distinct from ischemic necrosis of the femoral head. The objective of this study was to investigate ischemic necrosis of the femoral head as one potential cause of RDHD. Design and patients. In 600 patients who underwent MR imaging of the hip, 20 cases of ischemic necrosis involving the entire femoral head in 18 patients (3%) were retrospectively studied with routine radiography and MR imaging. All patients had surgically confirmed ischemic necrosis of the femoral head. Results and conclusions. All patients showed rapid destruction of the femoral head on routine radiography and MR imaging as compared with the gradual onset of clinical symptoms. Plain radiographs showed several bone fragments at the inferomedial aspect of the femoral head (75%), acetabular erosions (55%), eccentric depression at the lateral articular surface of the femoral head conforming to the adjacent acetabulum (35%), and mild osteoarthritis (15%). Bone sclerosis was often present at sites of impaction between the femoral head and the acetabulum. MR imaging showed marked distention of the joint capsule in all cases. In 14 of 20 cases, the contents of the joint space showed predominantly low or intermediate signal intensity on T1- and T2-weighted images. Ischemic necrosis involving the entire femoral head may represent one of the causes of RDHD.     

三种方案治疗小儿肺炎的药物经济学研究

目的：比较三种方案治疗小儿细菌性肺炎的效率（即费用－效果）。方法：2001年－2002年采用前瞻性随性临床试验A组50例，B组50例，C组50例作为分析模型，以深圳市二级甲等医院收费为标准，采用决策树的分析方法，进行费用一效果分析。结果：每治疗1例有效病人，A、B、C三组方案的期望成本分别为4707．45元，3052．51元，结论：同时考虑临床疗效及医疗费用，C组有最好的费用－效果，值得临床推广应用。