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991.
Ⅰ型膜型基质金属蛋白酶在癌细胞系中的表达及其与明胶酶A活?… 总被引:5,自引:0,他引:5
目的 探讨Ⅰ型膜型基质金属蛋白酶在人肿瘤细胞系中的表达情况及其与明胶酶的分泌和活化的关系。方法 运用逆转录巢式PCR,RNA印迹分析和蛋白质印迹分析的方法,检测MT1-MMP,mRN和MMP2蛋白在4个黑色素瘤,2个肺癌和2个前列腺癌细胞系中的表达水平。结果 MT1-MMPmRNA在所有癌细胞系中均有表达,但表达水平很不一致;在4个黑色素瘤细胞系中的表达水平明显高于肺癌和前列腺癌细胞系; 相似文献
992.
紫香驱蚴灵是预防日本血吸虫尾蚴感染的新型皮肤外用药。经毒性试验研究证实,大鼠口服LD50为2636(2207—3148)mg/kg,皮肤给药的LD50>5325mg/kg。家兔皮肤敷药部位未见红斑和水肿,豚鼠皮肤过敏试验,未见过敏反应,表明紫香驱蚴灵属低毒类、无刺激性、弱致敏性物质,局部皮肤外用是较安全的 相似文献
993.
由健康人外周血分离淋巴细胞及溶血处理后的全白细胞,以外源性表皮生长因子和甲硫氨酸脑啡肽培育后取细胞液帛晟滴片和滴膜,用生物素标记的c-foscDNA探针进行原位杂交和斑点印迹杂交。结果显示表皮生升因子和甲硫氨酸脑啡肽两组c-fos原癌基因的表达对照组增。 相似文献
994.
汉族男子体格及生殖器发育特点 总被引:1,自引:0,他引:1
2411例汉族男性大学生体格和生殖器的测量结果如下:阴茎周径8.17±0.64cm,阴茎长度7.43±1.04cm,阴茎牵长13.33±1.19cm,右睾丸容积17.91±4.09ml,左睾丸容积17.83±4.05ml,身高171.07±5.66cm,体重58.43±7.75kg.北方学生体格和生殖器发育均优于南方.城、县、乡学生的生殖器发育无明显差异,但城市学生体格发育优于农村.16岁后阴茎、睾丸大小变化不大,但生殖器的发育可持续到30岁. 相似文献
995.
硅凝胶人工晶体的生物相容性 总被引:3,自引:0,他引:3
本文参照国内外有关医用高分子材料的生物学评价试验方法,对国产医用级硅凝胶人工晶体作了系统的生物学评价。结果表明:硅凝胶人工晶体对眼及皮肤无刺激作用、无热原、无毒性、体外溶血率小于5%,对细胞生长有促进作用,长期植入皮下时,随植入时间延长,囊壁厚度逐渐变薄,炎性细胞反应30天基本消失。染色体及骨髓多染红细胞未受影响。因此,可以认为硅凝胶人工晶体有良好的生物相容性。 相似文献
996.
Effects of prolonged light exposure, GABA, and glycine on horizontal cell responses in tiger salamander retina 总被引:1,自引:0,他引:1
1. The effects of prolonged light exposure, gamma-aminobutyric acid (GABA), and glycine on the horizontal cell (HC) light responses were studied in the superfused flat-mounted isolated retinas of the larval tiger salamander. 2. Under prolonged dark-adapted conditions, the time-to-peak of the HC light response was approximately 2-4 s, and after the termination of prolonged (6-8 min) light exposure, the time-to-peak became approximately 0.5-1 s. 3. This prolonged light-induced change in response rise time was not observed in either photoreceptors or bipolar cells, and thus the change in HC response rise time may occur postsynaptically in the HC membrane. 4. Application of 100 microM of GABA mimicked prolonged darkness and reversibly slowed down the HC response rise time, and application of 100 microM bicuculline mimicked prolonged light exposure and reversibly sped up the HC response rise time. 5. Glycine also slowed down the HC response rise course, but its effect was not observable until the concentration was raised to 1-3 mM. Strychnine did not exert any effect on HC responses when applied alone, but it could reverse the glycine actions. 6. The actions of glycine disappeared in the presence of bicuculline, indicating that the GABA and glycine pathways were probably not independent. Application of 5-10 mM glycine produced an increase of flow of preloaded 3H-GABA from the retina. 7. These results indicate that GABA may be the primary modulator that slows down the kinetics of the postsynaptic membrane proteins in the HCs. The extracellular concentration of GABA is probably high in prolonged darkness, and it is low after prolonged light exposure. Glycine, when applied at high dose, results in an increase of GABA release that slows down the HC response time course. 8. Prolonged darkness and light exposure appear to modulate the HC response in the time domain through GABA, and this change in HC response time course is probably responsible for shaping the bipolar cell responses and making the retinal signals more transient under light-adapted conditions. 相似文献
997.
应用ABC法、LSAB法对144例乳腺癌及癌旁组织进行了c─erbB─2、p53基因蛋白表达的研究。结果:c─erbB─2表达阳性率为48.6%,浸润性导管癌阳性率最高(74.1%);其表达与肿瘤体积、淋巴结转移、组织分级、核分裂计数、临床分期呈正相关,与雌激素受体(ER)、孕激素受体(PR)状况呈负相关,表达者5年生存率显著低于表达阴性者.因而c─erbB─2表达的检测可作为评估乳腺癌预后的有力指标。p53表达的阳性率为24.7%,髓样癌阳性率较高(38.5%);p53表达与组织分级和淋巴结转移状况呈正相关;阳性率随肿瘤体积增大和临床分期升高而增加;在ER或PR阴性者中p53阳性率高于ER或PR阳性者。本文未发现c─erbB─2与p53表达的相关性;两者表达均阳性者与仅一种阳性者在肿瘤体积、淋巴结转移和临床分期方面差异无显著性。 相似文献
998.
999.
R. Wang Lingyun Wu Zunzhe Wang 《Pflügers Archiv : European journal of physiology》1997,434(3):285-291
The vasorelaxation induced by carbon monoxide (CO) has been demonstrated previously. Both a guanosine cyclic monophosphate
(cGMP) signalling pathway and cGMP-independent mechanisms have been proposed to be responsible for the vascular action of
CO. A direct effect of CO on the activity of calcium-activated K (KCa) channels in vascular smooth muscle cells (SMCs) and the underlying mechanisms were investigated in the present study. It
was found that CO hyperpolarized single SMCs isolated from rat tail arteries. The whole-cell outward K+ channel currents in vascular SMCs, but not in neuroblastoma cells, were enhanced by CO. Extracellularly or intracellularly
applied CO increased the open probability of single high-conductance KCa channels concentration-dependently without affecting the single channel conductance. Although it did not increase the resting
level of intracellular free calcium concentration, CO significantly enhanced the calcium sensitivity of single KCa channels in SMCs. Furthermore, the effect of CO on KCa channels was not mediated by cGMP or guanine nucleotide-binding proteins (G proteins, Gi/Go or Gs) in excised membrane patches. Our results suggest that the direct modulation of high-conductance KCa channels in vascular SMCs by CO may constitute a novel mechanism for the vascular effect of CO.
Received: 9 January 1997 / Received after revision: 21 February 1997 / Accepted: 10 March 1997 相似文献
1000.