小麦×大麦胚胎发育的研究——Ⅲ.小麦×大麦胎胚发育过程中淀粉的积累和动态

我们观察了小麦与大麦杂交胚胎发育过程中,雌蕊各个组成部分发生的淀粉积累和转移的动态。结果如下: 1.胚乳和杂种胚早期发育过程中,子房壁和胚囊中淀粉的积累和动态的趋势与其他学者所作小麦自交的情况基本相同。2.当胚乳细胞充满胚囊而胚没有分化时,子房壁中的淀粉已极少,当胚乳解体时,子房壁中淀粉已几乎消失。可见,子房壁中淀粉的迅速消失与胚乳的迅速败育是平行的。3.胚囊发育的停滞与败育跟子房壁组织中淀粉的积累及对胚囊营养的正常供应有密切关系。4.花柱、珠被、珠心组织及胚囊中的助细胞和反足细胞,在整个杂种胚和胚乳发育过程中,始终不存在淀粉粒。助细胞胚亦和助细胞一样,无淀粉粒的存在。     

昆明呈贡龙潭山第2地点的人化石和旧石器

在对呈贡县大渔区龙潭山第2地点的试掘中发现一枚人的下臼齿,它在形态上与现代人的不同,与北京猿人的也有所差别。它带有早期智人下第二乳臼齿的一些形态特征。一起发现的石制品中有石核、石片、砍砸器和刮削器。时代为晚更新世,距今30,500±800年。     

柱孢鱼腥藻的铁蛋白与棕色固氮菌的钼铁蛋白的交叉互补作用

纯化的柱孢鱼腥藻铁蛋白能够与棕色固氮菌的钼铁蛋白有效地交叉反应,展现较高的活性。此异源交叉反应的乙炔还原比活及放氢比活,分别是蓝藻同源互补比活的83.8及66.7％。比较藻铁蛋白与菌钼铁蛋白异源交叉反应及藻固氮酶组分之间的同源反应的动力学特点时发现,铁蛋白对钼铁蛋白的最佳克分子比数前者(异源交叉反应)较后者(藻同源反应)为高,前者为5,后者为1;但反应的时间进程两者差别不大。     

抗人肺癌细胞单克隆抗体的制备及其特性的研究

用人肺鳞癌细胞LTEP-78细胞系免疫Blab/c小鼠获得3株抗人肺癌细胞的单克隆抗体杂交瘤系。其中BLTI-01株经六次克隆化培养,体外传代8个月以上。BLTI-01与白细胞抗原及血型抗原基本上无交叉反应;与骨髓细胞无交叉反应;与癌胚抗原和胎甲球蛋白不相关;与肺鳞癌、肺腺癌细胞系及部分其它肿瘤细胞呈阳性反应。     

抗胃癌细胞系单克隆抗体PD4的初步研究

以胃癌细胞系MGC803免疫Balb/c小鼠,取其脾细胞与小鼠骨髓瘤细胞NS-1融合。经选择培养、筛选及克隆化,获得恒定地分泌抗胃癌细胞系单克隆抗体(MoAb)的杂交瘤细胞系PD4。MoAb PD4与3/4胃癌细胞系有强结合反应,与4/4肺癌细胞系有弱结合反应,但与淋巴细胞、ABO红细胞、骨髓细胞、二倍体成纤维细胞及经检测的其他肿瘤细胞均无反应。PD4抗原主要表达于靶细胞的膜上,不耐热,为分子量40kD的蛋白性抗原。该抗原与HLA抗原系统,血型抗原系统无关,亦不同于其他作者所报告的其他胃癌相关抗原。     

Sugar cane bagasse as a possible source of fermentable carbohydrates. I. Characterization of bagasse with regard to monosaccharide, hemicellulose, and amino acid composition

Individual monosaccharides present in bagasse hemicellulose were determined using HPLC and other chromatographic procedures. The presence of higher oligomers of the monosaccharides could also be determined. No single procedure can separate and identify all the naturally occurring monosaccharides. The pentosan fraction of bagasse wa successfully hydrolyzed and extracted with 5% (m/v)HCl, and the rate of release of individual monosaccharides was determined. Xylose was the main component in the hydrolyzates, while glucose, arabinose, and galactose present in the side chains of the pentosans were initially released at a fast rate. This treatment resulted in obtaining 229 mg/g xylose (85% of theoretical maximum) and 44 mg/g glucose from bagasse. Only arabinose (2.8 mg/g) and galactose (0.75 mg/g) was also present in detectable quantities. A total of 309 mg monosaccharides were obtained from 1 g of bagasse by this treatment. The results indicated that hydrolysis conditions for specific plant materials depend on the composition of the specific material being utilized. A part of the pentosan fraction (77.1%) was hydrolyzed at a high rate, while 22.9% was more stable and hydrolyzed more slowly. Although 39.8% dry bagasse could be obtained in solution by treatment with dilute alkali, only about 72% of the available hemicelluloses could be extracted in this way if the bagasse was not delignified beforehand. Amino acids and peptides or proteins were also extracted to very much the same with the alkali.     

用PO4细胞为靶细胞检测人血清中Epstein-Barr病毒IgA/MA抗体以诊断鼻咽癌

近年来,常用未经丙酮固定的、由丁酸和巴豆油激活的B95-8细胞或P3HR-1细胞为靶细胞,检测人血清中EB病毒IgA/MA抗体以早期诊断鼻咽癌,效果良好。但由于B95-8细胞含有多种EB病毒抗原,不能用丙酮固定,需多次离心沉淀,在浮悬状态下检测,技术比较复杂。     

细菌(Pseudomonas maltophilia)之绒毛膜促性腺激素(hCG)结合物质之研究

 细菌(Pseudomonas moltophilia)与hCG及LH有特异的亲和力,实验发现,细菌之生长曲线与hCG结合活性成平行关系,96小时达高峰,细菌之培养液中含有可溶性结合蛋白,该蛋白经硫酸铵沉淀(80％饱和度)、Sephadex G-100柱层析、DEAE-纤维素柱0.5mol/L NaCl梯度洗脱,再过Sepharose CL-AB柱,收集之活性部分经SDS电泳测得其分子量为70,000,凝胶层析测Stokes radius为41A,Schiff氏染色未见着色带。     

腺苷酸激酶在我国九个民族中的多态分布

用淀粉胶电泳及特异染色的方法,对我国9个民族的腺苷酸激酶(AK)多态分布进行了测定。9个民族中维吾尔族AK表型分布具有多态性。维吾尔族中AK_1~1基因频率为0.965,AK_1~2基因频率为0.035,而侗、回、白、土家、苗、彝、藏、满等8个民族的AK_1~2均未达到多态水平。在9个民族中AK_1表型分布均符合Hardy-Weinberg平衡,并且未发现其它罕见表型。     

Development of gluconeogenesis from different substrates in newborn rabbit hepatocytes

The rates of glucose production from various substrates entering gluconeogenesis at different steps were investigated in hepatocytes isolated from term-fetus and newborn rabbits fasted during the first 2 days of life. The data were compared to the rate of glucose production measured in hepatocytes from young rabbits (50-60 days) starved for 48 h. The net production of glucose from substrates (lactate, pyruvate, propionate, alanine) entering gluconeogenesis below phosphoenolpyruvate was very low at birth and increased during the first day of life, in relation with an increased cytosolic phosphoenolpyruvate carboxykinase activity. The net production of glucose from precursors entering gluconeogenesis at the level of triose phosphates (dihydroxyacetone, fructose) was low at birth but a maximal capacity for gluconeogenesis was reached within 6 h after birth. This enhanced gluconeogenic capacity was associated with a fall in hepatic fructose 2,6-bisphosphate concentration and a reduced glycolytic flux. In contrast, a high glucose production from galactose was already present at birth and did not rise at 24 or 48 h after delivery. These results suggest that the development of gluconeogenic capacity in hepatocytes isolated from newborn rabbit is dependent upon two factors, a decrease in the F2,6-P2 concentration which reduces the glycolytic flux and an increase in the activity of cytosolic phosphoenolpyruvate carboxykinase.