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.     

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。     

电刺激黑质对脑干伤害性单位放电的影响

本实验采用单细胞外记录神经元单位放电的方法，在Ｗｉｓｔａｒ大鼠上观察到网状巨细胞核。一区伤害性神经元５７个，其中伤害兴奋性神经元（ＮＥＮ）４２个，伤害抑制性神经元（ＮＩＮ）１５个。电刺激黑质对ＮＥＮ（２９）和ＮＩＮ（８的放电呈抑制作用，其反应百分率分别由刺激黑质第１分钟时的１．０±２．１％和－２０．４±６．２％，降到第５分钟时的－８３．６±１２．３％和－６５．４±１０．７％（Ｐ＜０．０１）。刺激黑质对少数ＮＥＮ（１３）和ＮＩＮ（７）的放电有兴奋作用，其值分别由第］分钟时的２０．５±７．３％和１．０±３．４％，升高到第５分钟时的７４．５±１０．７％和２１，５±８．６％（Ｐ＜０．０５）。氟哌啶醇注入ＰＡＧ腹外侧部可阻断刺激黑质的效应，这提示从黑质到网状巨细胞核α－区存在着一条痛调制通路，而且这种通路的递质是多巴胺能的。     

光动力学疗法与局部化疗联合治疗进展期食管贲门癌

作应用光动力学疗法（ＰＤＴ）对进展期食管贲门癌５５例进行治疗，并对其中１５例联合应用内镜下局部注射抗癌药物。对每一患均先静脉滴注血卟啉衍生物（ＨＰＤ）５ｍｇ／ｋｇ，于用药后２４，４８和７２ｈ分别用波长６３０ｎｍ的铜蒸汽激光照射肿瘤部位。联合治疗组除ＰＤＴ治疗外，于每次光照前肿瘤局部注射５－Ｆｕ２５０～５００ｍｇ。结果：联合治疗组的近期显效率高于单纯ＰＤＴ组（Ｐ〈０．０５）。病例随访６～１６月，     

主动吸入药物烟对大鼠一氧化氮的影响

目的　探讨主动吸入药物烟对大鼠NO的影响。方法　制备大鼠主动吸烟模型 ,采用硝酸还原酶法测定各组大鼠血清、肺、心肌及脑组织的NO含量。结果　非药物烟组大鼠血清、肺、心肌及脑组织中NO含量明显低于非给烟对照组 ,药物烟高、中剂量组NO含量明显高于非药物烟组 ,接近非给烟对照组。结论　吸烟对大鼠血液、肺、心肌及脑组织有不同程度的损伤作用 ,使NO含量降低 ;药物烟具有一定的保护和防止NO含量降低的作用。     

Comparison of fMRI statistical software packages and strategies for analysis of images containing random and stimulus-correlated motion.

The objectives of this study were to use computer-generated phantoms containing real subject motion to: (1) compare the sensitivity of four commonly used fMRI software packages and (2) compare the sensitivity of three statistical analysis strategies with respect to motion correction. The results suggest that all four packages perform similarly in fMRI statistical analysis with SPM2 having slightly higher sensitivity. The most sensitive analysis technique was to perform motion correction and include the realignment parameters as regressors in the general linear model. This approach applies to all four packages examined and can be most beneficial when stimulus-correlated motion is present.     

668颗后牙镍铬合金PFM边缘适合性的临床观察

目的：观察采用2种边缘形式的后牙烤瓷熔附金属全冠边缘适合性和对牙龈健康的影响.方法：对668颗后牙,分别采用2种边缘形式的后牙烤瓷熔附金属全冠（单冠或桥的基牙）在修复2年后进行复查,检测其边缘适合性及牙龈指数（GI）和牙周探诊深度（PD）,用统计学方法分析修复体边缘形式与牙龈病变间的关系.结果：采用羽状边缘360°金属脚边的PFM边缘适合性明显优于凹面肩台型边缘PFM,凹面肩台型边缘的PFM的牙龈病变发生率,明显高于羽状边缘360°金属脚边的PFM,而边缘适合性差者较适合性好者牙龈病变发生率显著增高.结论：后牙PFM的边缘采用羽状边缘360°金属脚边是一种好的选择.     

Alpha-tocopherol and beta-carotene do not protect marmosets against the dopaminergic neurotoxicity of N-methyl-4-phenyl-1,2,3,6-tetrahydropyridine

Idiopathic Parkinson's disease (PD) may possibly be caused by one or more unidentified neurotoxins present in the environment, or formed endogenously, which progressively damage dopaminergic nigrostriatal neurons. N-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is an experimental neurotoxin which produces biochemical and neuropathological changes in humans, lower primates and mice that closely resemble those found in PD. Because the mechanisms of neuronal damage in both idiopathic PD and in the MPTP model of PD may involve free radical formation in the substantia nigra, antioxidants might protect dopaminergic neurons. Previously, we found that both alpha-tocopherol and beta-carotene partially protected mice against MPTP. However, in the experiments described in this paper, neither alpha-tocopherol nor beta-carotene, each administered in massive doses, had any demonstrable protective effect for dopaminergic nigrostriatal neurons in marmosets injected with low doses of MPTP. Without more knowledge about the identity of the neurotoxin(s) causing idiopathic PD, and their mechanism of action, it is not possible at this time to predict whether these 2 antioxidants might be clinically useful in preventing or ameliorating PD.     

99m TC-MIBI动态显像对非小细胞肺癌化疗疗效的预测价值初探

目的 探讨^99mTC-MIBI动态显像对非小细胞肺癌化疗疗效的预测价值。方法 对确诊为不能手术的非小细胞肺癌患者化疗前,静脉注射740mbq ^99mTC-MIBI后分别于30min,2h行SPECT动态扫描,计算早期/晚期肿瘤组织与对侧正常肺组织的放射活性比（T/Ne,T/Nd）,全身采用卡铂/顺铂＋VP16化疗3周期,随后复查胸部CT,评判化疗疗效及其与^99mTC-MIBI动态显像的关系。结果 78例NSCLC符合入选标准,并完成化疗方案,66例呈阳性显像,12例阴性显像,66例阳性显像中化疗有效率为90.7%,阴性显像12例中化疗全部进展,两者比较差异有显著性（P〈0.01）。结论 ^99mTC-MIBI动态显像的放射活性越高,化疗效果越好,对非小细胞肺癌化疗疗效有预测价值,可为合理制定治疗方案提供重要依据。