脑肿瘤抑制因子的功能研究

本文证明了胎脑组织中存在一类可以抑制人白血病细胞系的生长的低分子天然抑癌物．这种抑瘤物抑制活性分布在小于１０ｋＤａ组分,经Ｓｅｐｈａｄｅｘ－Ｇ２５凝胶过滤可分离为单一组分,且具有广谱的抗肿瘤效应．体外可抑制人白血病、肝癌、胃癌细胞系和小鼠粒、单核和淋巴系白血病细胞,而对人骨髓ＣＦＵ－ＧＭ和小鼠骨髓ＣＦＵ—ＧＭ的抑制作用较弱。     

新生牛肝中的低分子量抑瘤物对白血病干细胞影响的初步研究

新生牛肝中的低分子量抑瘤物对白血病干细胞影响的初步研究王福生,吴祖泽（北京军事医学科学院放射医学研究所１００８５０）近来,我们报道了新生牛肝中存在着一类天然低分子量的肿瘤抑制物（ＢＬＳ）,后者对体外培养的白血病细胞（系）及原代白血病祖细胞（Ｌ－ＣＦＵ...     

人胎肝中两种抑制肿瘤细胞生长活性成分的分离鉴定及功能研究

胎儿组织中存在低分子肿瘤抑制物。胎肝细胞的甲醇－丙酮提取物中保留有大部分抑瘤活性。用体外液体培养条件下对人急性粒系白血病细胞系（ＨＬ－６０）的抑制作用为指标,跟踪分离过程。提取物经反相Ｃ１８中压液相色谱、Ｓｅｐｈａｄｅｘ ＬＨ－２０凝胶色谱及正相高效液相色谱分离得到两种活性物质,经ＮＭＲ和ＨＲＭＳ鉴定为７－酮基胆固醇（７－ｋｅｔｏｃｈｏｌｅｓｔｅｒｏｌ,７－ＫＣ）和７－β－羟基胆固醇（７－β－ｈｙ     

人胎肝中低分子抑瘤物的分离纯化、结构鉴定及其对肿瘤细胞生长的选择性抑制作用

在胎儿组织中存在一类低分子肿瘤抑制物。胎肝细胞的甲醇－丙酮提取物中保留有大部分抑瘤活性。用体外液体培养条件下对人急性粒系白血病细胞系（ＨＬ－６０）的抑制作用为指标,跟踪指导分离过程。提取物经反相Ｃ１８中压液相色谱、ＳｅｐｈａｄｅｘＬＨ－２０凝胶色谱及氨基键合相高效液相色谱分离得到一纯活性物质,经ＮＭＲ和ＭＳ鉴定为７－酮基胆固醇（７－ｋｅｔｏｃｂｌｅｓｔｅｒｏｌ,７－ＫＣ）。体外琼脂培养条件下７－ＫＣ对小鼠ＷＥＨ１－３和Ｓ－１８０细胞较对正常小鼠骨髓粒一巨噬系祖细胞有更强的抑制增殖及集落生成作用。７－ＫＣ对ＨＬ－６０细胞增殖较对正常人骨髓ＣＦＵ－ＧＭ有更强的抑制作用。     

IL－7对早期胸腺细胞发育的作用

胸腺基质细胞分泌白细胞介素７（ＩＬ－７）。ＩＬ－７是早期Ｔ细胞的重要生长因子之一。它能选择性促进ＣＤ４－ＣＤ８－和ＣＤ４＋ＣＤ８－／ＣＤ４－ＣＤ８＋细胞增殖。ＩＬ－７主要维持早期前体Ｔ细胞存活,同时保持其Ｔ前体细胞潜能。ＩＬ－７对胸腺细胞分化的作用目前仍有争议。     

人胎肝细胞分泌的低分子抑瘤物对白血病细胞的抑制作用

本工作证明了在胎儿组织中存在一类低分子天然肿瘤抑制物,它是胎儿组织细胞生成和分泌的,对瘤株细胞和原代白血病细胞有选择性抑制作用。初发期或复发期急性非淋巴细胞白血病患者的骨髓在体外液体培养条件下与肝细胞上清及其甲醇提取物共同孵育4d,可使所有病例的骨髓AML—CFU降低到不可检出的程度。因而,低分子天然抑瘤物是天然肿瘤免疫中的一个组成部分,它在肿瘤的诊断和治疗中有着深远的意义。     

IL—7对早期胸腺细胞发育的作用

胸腺基质细胞分泌白细胞介素７（ＩＬ－７）。ＩＬ－７是早期Ｔ细胞的重要生长因子之一。它能选择性促进ＣＤ４＾－ＣＤ８＾－和ＣＤ４＾＋ＣＤ８＾－／ＣＤ４＾－ＣＤ８＾＋细胞增殖。ＩＬ－７主要维持早期前体Ｔ细胞存活,同时保持其Ｔ前体细胞潜能。ＩＬ－７结胸腺细胞分化的作用目前仍有争议。     

乙酰胆碱对大鼠体外抗体生成的影响

目的：观察不同浓度乙酰胆碱（ＡＣｈ,１０－１０～１０－５ｍｏｌ／Ｌ）对大鼠体外抗体生成的影响,并初步探讨其作用机制,从细胞水平了解乙酰胆碱与免疫功能之间的关系。方法：用体外抗体生成的检测方法,用绵羊红细胞（ＳＲＢＣ）刺激大鼠肠系膜淋巴结Ｂ细胞转化成抗体形成细胞（ＡＦＣ）,然后检测其抗体生成量。结果：①１０－１０～１０－７ｍｏｌ／ＬＡＣｈ能显著抑制体外抗体生成,其中１０－８和１０－７ｍｏｌ／ＬＡＣｈ的作用较强,而１０－６和１０－５ｍｏｌ／ＬＡＣｈ无明显的抑制作用;②Ｍ型胆碱能受体激动剂毛果芸香碱（１０－８和１０－７ｍｏｌ／Ｌ）能明显减弱体外抗体生成,而Ｎ型受体激动剂烟碱（１０－８和１０－７ｍｏｌ／Ｌ）没有显著的减弱作用,Ｍ型受体拮抗剂阿托品（１０－７和１０－６ｍｏｌ／Ｌ）可完全阻断ＡＣｈ抑制体外抗体生成的作用;③ＡＣｈ分别在Ｂ细胞用ＳＲＢＣ刺激后３～４８ｈ中的６个不同时间与淋巴细胞作用,其抗体生成仍然是减少的。结论：ＡＣｈ可非浓度依赖性地抑制大鼠的体外抗体生成;此作用可能由Ｂ细胞上的Ｍ型胆碱能受体介导;且ＡＣｈ可能主要影响Ｂ细胞转化的后期过程。     

新生牛肝中低分子抑瘤物影响白血病细胞生长的实验研究

新生牛肝经匀浆、离心和分级超滤后,得到分子量≤1.0kDa的、耐热的成分——新生牛肝抑瘤物(new-bom calfliver suppressor,BLS-1)。对BLS-1的生物学活性进行了检测,结果表明在体外液体和半固体琼脂培养条件下,它对人和小鼠白血病细胞系(如HL-60、L833 和 P388 等)的生长均有明显的抑制作用,并存在着一定的量效关系;与同样条件下BLS-1对人和小鼠正常粒-巨噬系祖细胞的抑制作用相比较,BLS-1对白血病细胞生长的抑制作用具有较强的选择性。进一步观察了BLS-1对5例急性非淋巴细胞白血病病人骨髓的原代白血病细胞集落(leukemic blast progenitor,L-CFU)生成的影响,结果表明,当BLS-1的浓度达到500μg/ml时,L-CFU的生成受到明显抑制。上述研究结果提示,在新生牛肝中可能存在类似于人胎儿肝脏中的一类低分子天然抑瘤物。     

HDL受体和肝性脂酶在肝选择性摄取HDL_2－CE中的协同作用

体外重组３Ｈ－ＣＥ－无ＡｐｏＥ－ＨＤＬ２（ｒＨＤＬ２）保持天然ＨＤＬ２生物活性。大鼠肝窦状隙细胞与ｒＨＤＬ２３７℃培养３ｈ（正常组）;细胞内吞ｃｐｍ为９９５±１４７（ｘ±Ｓ．Ｄ．,ｎ＝２）。细胞进一步９７℃培养２ｈ．释放三氯醋酸（ＴＣＡ）沉淀和ＴＣＡ上清液中ｃｐｍ为７８±３２和１２±９。Ｎ－乙酰咪唑修饰组为３３９±６２、１９±１１和９±５。肝素处理组为５４２±７８、３４±１４和９±８。实验结果提示：（１）肝窦状隙细胞通过ＨＤＬ受体内吞ＨＤＬ２摄取ＨＤＬ２－ＣＥ,并通过逆向胞饮将ＨＤＬ３排出体外．（２）肝性脂酶（ＨＬ）直接介导细胞选择性摄取ＨＤＬ２－ＣＥ,导致ＨＤＬ３生成．（３）ＨＬ和ＨＤＬ受体在介导细胞选择性摄取ＨＤＬ２－ＣＥ中具有协同作用。     

Investigation of the mechanism of temperature sensitivity of the electroreceptors of ampullae of lorenzini

In experiments on Black Sea skates (Raja clavata), the potential of the receptor epithelium of the ampullae of Lorenzini and spike activity of single nerve fibers connected to them were investigated during electrical and temperature stimulation. Usually the potential within the canal was between 0 and –2 mV, and the input resistance of the ampulla 250–400 k. Heating of the region of the receptor epithelium was accompanied by a negative wave of potential, an increase in input resistance, and inhibition of spike activity. With worsening of the animal's condition the transepithelial potential became positive (up to +10 mV) but the input resistance of the ampulla during stimulation with a positive current was nonlinear in some cases: a regenerative spike of positive polarity appeared in the channel. During heating, the spike response was sometimes reversed in sign. It is suggested that fluctuations of the transepithelial potential and spike responses to temperature stimulation reflect changes in the potential difference on the basal membrane of the receptor cells, which is described by a relationship of the Nernst's or Goldman's equation type.I. P. Pavlov Institute of Physiology, Academy of Sciences of the USSR, Leningrad. I. M. Sechenov, Institute of Evolutionary Physiology and Biochemistry, Academy of Sciences of the USSR, Leningrad. Pacific Institute of Oceanology, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Neirofiziologiya, Vol. 12, No. 1, pp. 67–74, January–February, 1980.     

Determination of stoichiometry of radioiodination of proteins

A sensitive method for the detection of small quantities of hydrophobic antioxidant free radical scavengers such as butylatedhydroxytoluene (BHT) and butylatedhydroxyanisole (BHA) in aqueous samples is described. The procedure involves extraction of the hydrophobic free radical scavenger into an organic solvent phase, followed by the subsequent reaction of an aliquot of this extract with the stable cation radical tris(p-bromophenyl)amminium hexachloroantimonate (TBACA). In experiments with BHT and BHA, the loss of TBACA absorbance at 730 nm was found to be linearly proportional to the amount of antioxidant added, with quantities of BHT as small as 200 pmol being easily detectable. In aqueous suspensions of dimyristoylphosphatidylcholine vesicles, assays of the aqueous BHT concentration showed that BHT partitioned strongly into the membrane phase, achieving very high BHT/phospholipid ratios. For a given concentration of BHT, partitioning into the membrane phase was greater in large, multilamellar liposomes than in either small, single-walled vesicles or in purified rat brain synaptic vesicle membranes. Direct assay of BHT and BHA in phospholipid membranes, however, was complicated by a nonspecific interaction between TBACA and the phospholipid.