Expression of neurotrophins in the adult spinal cord in vivo

Potential roles of trophins in the normal and injured spinal cord are largely undefined. However, a number of recent studies suggest that adult spinal cord expresses neurotrophin receptors and responds to the neurotrophins, brain-derived neurotrophic factor (BDNF) and neurotrophin 3 (NT3), particularly after injury. The data indicate that trophins may enhance regrowth after damage and may represent a new therapeutic approach to injury. Neurotrophins are reportedly present in the spinal cord, but the cellular localization is unknown. This information is critical to begin delineating mechanisms of actions. To approach this problem, we examined whether spinal cord glia express BDNF and NT3 in vivo and have begun to define cellular distribution. Specific antibodies directed against the neurotrophins were utilized to visualize neurotrophin protein. Initial studies indicated that small cells in the white matter of adult rat spinal cord express BDNF and NT3. Large neurotrophin-positive neurons were also identified in the ventral cord. To identify the neurotrophin-positive cells, co-localization studies were performed utilizing neurotrophin polyclonal antisera together with monoclonal antibodies directed against the astrocyte marker, glial fibrillary acidic protein (GFAP). In the white matter of adult spinal cord, GFAP-positive and GFAP-negative cells expressed BDNF and NT3. Our study suggests that astrocyte and non-astrocyte cells provide trophic support to the adult spinal cord.     

重组人神经营养因子-4/5蛋白抗三氧化二砷神经毒作用

目的初步观察重组人神经营养因子-4／5（hNT－4／5）蛋白对三氧化二砷毒性的抑制作用。方法利用hNT－4／5蛋白具有抗神经毒性的特点,采用本实验室克隆表达及部分纯化的具有天然hNT－4／5蛋白生物学活性的重组hNT-4／5蛋白,以不同水平的重组hNT4／5蛋白（0－100μl）与不同浓度的As2O3（0－160μmol／L）同时加入各组鸡胚前脑神经细胞和PC12细胞培养液中共同孵育24－48小时,观察其对染毒鸡胚前脑神经细胞存活和PC12细胞突起生长的影响作用。结果在鸡胚前脑神经细胞和PC12细胞中与As2O3共同培养48小时后,对照组与实验组的细胞存活率差异有显著性,而且细胞存活率和突起数目随hNT－4／5浓度增高而提高和增加。结论初步观察到重组hNT4／5蛋白具有抑制As2O3的毒性作用,为从基因工程途径寻找抗环境毒物因子提供了依据。     

分子流行病学在职业性致癌研究中的应用

作者综合描述了分子流行病学基本概念的主要内容与传统流行病学的差异。阐明：１．分子流行病学是分子生物学与流行病学相结合的边缘科学;２．化学致癌物在体内的生成量及其与生物大分子结合的生物有效量与癌症发生有关;３．染色体异常综合症是癌症早期的生物效应;癌基因激活,抗癌基因失活是被启动了的细胞恶性转化所必须的;４．先天和后天获得的宿主因素可影响人体对致癌剂的易感性;５．建立生物样品库,进行前瞻队列研究可提供连续性观察结果及癌前癌后比较,为因果关系的时间顺序提供有效的依据     

微波消融犬室性心动过速的实验研究

观察微波消融犬室性心动过速（简称室速）疗效和微波消融对血液动力学的影响。健康犬４０只,随机分成５组,Ⅰ组（对照组,ｎ＝８）,Ⅱ、Ⅲ、Ⅳ和Ⅴ组（消融组,ｎ＝８）,由股动脉、股静脉穿刺进行血液动力学监测。用０．０１ｍｌ０．０３％乌头碱注入心室壁诱发室性心动过速。消融释放功率和时间Ⅱ组为４０Ｗ×３０ｓ,Ⅲ组为４０Ｗ×６０ｓ,Ⅳ组为８０Ｗ×３０ｓ,Ⅴ组为８０Ｗ×６０ｓ。结果：自发放微波能量至室速终止时间Ⅱ、Ⅲ组为（１０．１±２．４）ｓ,与对照组比,Ｐ＜０．００１;Ⅳ、Ⅴ组为（５．３±１．５）ｓ,与对照组比,Ｐ＜０．００１。消融前后血液动力学各项指标差异无统计学意义（Ｐ＞０．０５）,消融后组间血液动力学各项指标差异无统计学意义（Ｐ＞０．０５）。微波产生的心肌损伤,显微镜下观察均为凝固性坏死,与周围组织存在清晰的界限。结论：微波消融室速具有较好的疗效,消融能量与时间在一定范围内对血液动力学无明显影响,可望成为室速治疗的１种新方法。     

室内空气污染与女性肺癌

为探讨室内空气燃料污染,被动吸烟,烹饪与女性肺癌的关系。搜索经省级医院确诊的哈尔滨市女性原发性肺癌１１５例及对照１２４例进行调查及单因素Ｌｏｇｉｓｔｉｃ回归分析。结果表明冬天取暖和做饭室内有烟,被动吸烟年限均与女性肺癌有关系显著,女性患肺癌危险性与终动吸烟总量呈明显的剂量－效应关系。     

学生心理障碍测试分析系统及其应用的研究

目的研究学生心理障碍简易测试分析系统,促进学生心理健康发展。方法采用现况、回顾和前瞻性研究方法,对多种心理测试量表进行筛选与对照比较研究,资料用SAS系统分析。结果经4年考核人为采用EPQ和SCL-90综合评判的测试分析系统科学、简便、实用。结论该系统有推广应用价值,适用于中学、大学学生心理健康档案的建立与管理。     

利用独立准直器开展调强放疗算法研究

研究利用独立准直器调整射野强度分布。设计了两种递推的办法来计算射野处序列,采用模拟退火算法优化射野片的照射顺序。并以在Ｖａｒｉａｎ ６００Ｃ轲速器上实施三个临床调强射野为例,估计ＩＣ调强放疗的照射时间。照射时间一般在５至１０ｍｉｎ。它近似与机器剂量率成反比,并受调强算法,矩阵元素大小以及强度分级数的影响。     

Gene cloning and sequencing of BmK AS and BmK AS-1, two novel neurotoxins from the scorpion Buthus martensi Karsch.

Based on the known amino acid sequences of BmK AS and BmK AS-1, the gene specific primers were designed and synthesized for 3' and 5' RACE (Rapid Amplification of cDNA Ends). Their partial cDNA fragments obtained by 3' and 5' RACE were cloned and sequenced, and the full length cDNA sequences of BmK AS and BmK AS-1 were then completed by overlapping their two partial cDNA sequences, respectively. The predicted amino acid sequences both consist of 85 amino acid residues including a putative signal peptide of 19 residues and a mature toxin of 66 residues. They are different in 17 amino acid residues, among them 11 residues in the mature toxin. The predicted amino acid sequences of BmK AS and BmK AS-1 were almost consistent with those determined and revised (personal communication), only different in one and two residues at their COO-terminal parts, respectively. Based on the determined cDNA sequences, and using the total DNAs isolated from the scorpion venom glands as a template, the genomic DNAs of BmK AS and BmK AS-1 were also amplified by PCR and sequenced. It showed that no intron was inserted in their open reading frames, while in the exon of signal peptide sequences of other Na+, K+ and Cl- channel toxins from the same scorpion, an intron is usually found. However, the Northern blot hybridization results indicated that the sizes of their mRNA should be around 800 bp. Their extra sequences around 400 bp which might function as an intron should be located at their 5' untranslated regions.     

粉防己碱与阿霉素或长春新碱联合用药的体外抗癌增效作用

AIM: To study the interaction between tetrandrine (Tet) and doxorubicin (Dox) or vincristine (Vin) against human breast cancer cell lines MCF-7 and MCF-7/Dox or human nasopharyngeal cancer cell lines KB and KBV200 in vitro. METHODS: Anticancer activities of a drug alone and a drug combination of Tet and Dox or Vin were determined by tetrazolium (MTT) method. The interaction between Tet and Dox or Vin was evaluated by both a value of a sum of fractional inhibitory concentration (SFIC) and an isobologram method. RESULTS: The SFIC values of the three-different-ratio combinations between Tet and Dox ranged from 0.14 to 0.38 for MCF-7, and 0.10 to 0.29 for MCF-7/Dox; those of Tet-Vin combinations ranged from 0.21 to 0.37 for KB, and 0.32 to 0.63 for KBV200. All the SFIC values of the combination between Tet and Dox or Vin were less than 1.0 when the 3 ratios of the 2 drugs in combination were used, and the shapes of isobolic curves obtained from the combination were concave. CONCLUSION: The interaction between Tet and Dox or Vin against the human cancer cells was markedly synergistic.     

左旋四氢巴马汀对单个豚鼠心室肌细胞钙电流的阻滞作用

AIM: To study the effect of l-tetrahydropalmatine (l-THP) on L-type calcium channel. METHODS: Patch clamp technique (whole cell recording) was used to record L-Ca2+ current in single cardiac myocyte. RESULTS: 1) l-THP 1, 10, and 100 micromol.L-1 reduced ICa-max from (999 +/- 93) pA to (700 +/- 111) pA, (582 +/- 66) pA, and (420 +/- 112) pA (n = 6, P < 0.01), respectively. 2) l-THP reduced the voltage at half-maximal inactivation (V1/2) of L-Ca2+ channel to more negative potentials by 9 mV (n = 5, P < 0.05). 3) l-THP caused both tonic and use-dependent reduction of Ca2+ current. Tonic block of l-THP on Ca2+ current was 46% +/- 8% (n = 6, P < 0.01). The degree of use dependent blocking was 13.5% +/- 2.4% (n = 6, P < 0.05) at 1 Hz, the degree increased to 44% +/- 5% (n = 6, P < 0.01) at 3 Hz. 4) l-THP delayed half-recovery time of Ca2+ channel recovery from inactivity from (94 +/- 39) ms to (170 +/- 42) ms(n = 6, P < 0.01). CONCLUSION: l-THP has a moderate inhibitory effect on L-Ca2+ current.