蚯蚓组织苹果酸脱氢酶同功酶及酯酶同功酶的电泳研究

本文以栉盲环毛蚓、秉氏环毛蚓和背暗异唇蚓为实验材料,分别取得适量的体壁、环带、肠、砂囊和前列腺组织,应用聚丙烯酰胺凝胶圆盘电泳-特异性组织化学染色技术的方法,分析两种同功酶(MDH和EST),并对EST同功酶进行二维排序.得出结果表明,三种蚯蚓的苹果酸脱氢酶谱较简单,种间和组织间MDH同功酶的差异不显著,均不表现出组织和种属的特异性.三种蚯蚓五种组织中的EST同功酶谱都较复杂,不同种的相同组织在酶谱上均有显著差异,充分表示组织和种属的特异性.因此,EST同功酶的种属特异性能很好地表示出陆栖寡毛类的亲缘关系,应用分子水平的指标来进行分类,有助于解决传统经典分类系统中的有争议问题,促进分类学的进一步发展.     

肿瘤组织块接种法建立人脑肿瘤裸小鼠移植模型的研究

以脑肿瘤患者肿瘤组织块接种法建立三种人脑脑肿瘤裸小鼠移植模型，成功率为４２．８％。移植瘤在质地、血供、间质结构、生长特征等方面良好保持了原肿瘤特性，其直接、快速、稳定地建立模型的方法优于肿瘤细胞系接种法。较高的建模型成功率有赖于快速接种、较大接种量、长期观察、良好的净化条件等因素。     

盐胁迫下沙枣组织再生芽的分化和生长

沙枣的各种外植体在 B_5+0.2mg/l IBA+3mg/l KT 的培养基上进行组织培养;20天后可分化出大量再生芽,待长至0.3～0.5cm 时,转入 MS 培养基上,可形成完整的再生植株.在试验时,把再生芽分别转入含0、0.3、0.5、0.8、1.0(%)NaCl 的 B_5培养基中培养,发现在0.3%NaCl 下生长分化良好.随着 NaCl 含量的提高,再生芽分化率、生长率均下降。     

绞股蓝的组织培养及细胞组织学观察

以MS为基本培养基,通过改变激素种类和浓度成功地从带腋芽的茎段诱导了丛芽.实验表明:2～4mg·L~(-1)BA(6-苄基氨基嘌呤),0.05mg·L~(-1)NAA(萘乙酸)是诱导丛芽所必需的,BA与KT(6-糠基嘌呤)合用效果最佳。对丛芽发生、发展的组织学观察表明丛芽来自叶腋基部的分生组织细胞、丛芽基部的愈伤组织、丛芽新生叶片表层恢复分生能力的叶肉细胞.再生植株的染色体数与栽培植株相等,2n=22,但亦偶有三倍体和四倍体.大量增殖丛芽形成的封顶芽,可通过降低培养基的无机盐、BA和蔗糖浓度,加入0.1～1mg·L~(-1)GA_3(赤霉素),并暗培养1周促进节间伸长.     

抑素作用下三分量组织生长模型的行波解

本文运用反应扩散系统的行波解理论,研究一个受抑素影响的三分量Logistic型组织生长模型方程.讨论了方程定态的稳定性和行波解的存在性,运用小参数展开法求出近似波前解,并通过数值模拟证明波速为2.0的波是全局稳定的.最后得出结论;生长组织中的自分泌抑素并不影响Logistic组织的整体增殖速度,而只改变组织的局域生长速度和减小组织的最大密度.     

Minoxidil-induced cardiac hypertrophy in guinea pigs

To investigate whether during cardiac hypertrophy changes occur in contractile protein composition and in mechanical and energetic properties of the myocardium, contractile protein composition, isometric force and adenosine triphosphate (ATP) consumption were studied in control and hypertrophied guinea-pig hearts. Cardiac hypertrophy was induced by adding minoxidil (120 or 200 mg/l) to the drinking water. Protein analysis was performed by one-dimensional gel electrophoresis. The myosin heavy-chain (MHC) composition was determined in an enzyme-linked immunosorbent assay (ELISA). ATP consumption and force development were simultaneously measured during isometric contraction in chemically skinned trabeculae. Histochemical analysis of cross-sectional area of cardiomyocytes and interstitial space was performed on the left ventricular tissue of 200 mg/l minoxidil-treated and control guinea pigs. Minoxidil treatment (120 and 200 mg/l) significantly increased left ventricular dry weight normalized for body weight by 19 ± 4 and 24 ± 4%, respectively. No significant differences were found in the cellular cross-sectional area, while interstitial space was slightly decreased in minoxidil-treated hearts. In left ventricular trabeculae of 200 mg/l minoxidil-treated guinea pigs, ATPase activity was slightly less than in those of control guinea pigs, whereas force did not differ significantly. Calcium sensitivity of force and ATPase activity were not affected by minoxidil treatment. Gel electrophoresis revealed no difference in contractile protein composition, but a tendency towards a lower amount of α-MHC in the minoxidil-treated hearts was found in ELISA. Received 1 February 1999; accepted 15 March 1999     

用回波重建法分离软组织的超声反射波与散射波

提出用计算机仿真重建反射回波，以分离软组织超声反射与散射波的方法。该法不仅 能考虑到超声波在传播过程中幅度的衰减，还能够考虑到频率构成的变化。为实现该法，在以 前模型的基础上建立了各层衰减系数不同的分层介质超声传播模型，形成了估计各层衰减系 数与各界面反射系数的有效方法。为提高衰减系数估计中谱分析对噪声的稳健性，提出并采用 了冗余自相关算法。用计算机仿真实验与生物组织仿真模块实验验证了上述方法的有效性。