Human myeloma light chains with increased molecular weight: high frequency among lambda chains

The discovery of a human myeloma protein comprising a kappa L-chain with an increased mol. wt of 30,000) (Bouvet et. al., 1980) prompted investigations on the incidence of such heavier L-chains among other human myeloma proteins. In 105 samples examined, 34 were found to have L-chains heavier than normal (23,000-24,000), ranging from 25,000 up to 31,000, and five of lighter mol. wt (21,000-22,000). These mol. wt abnormalities were detected by electrophoresis in sodium dodecyl sulfate 10% polyacrylamide gels (SDS-PAGE) after reduction with 2-mercaptoethanol. The mol. wt of three of the heavier kappa or lambda chains was also estimated by filtration through a Sephadex G100 column and by sedimentation equilibrium. All three methods indicated a mol. wt increase of about 15-25% as compared with the usual mol. wt. The distribution of the high mol. wt chains among all L-chains examined was found to be 11 out of 62 kappa chains (17.7%) and 23 out of 43 lambda chains (53%) (P less than 0.001). A preferential association of such L-chains with H-chains producing multiple bands in SDS-PAGE (P less than 0.01) and an association between multiple L-chain and multiple H-chain band (P less than 0.05) were also observed. In contrast, no abnormal L-chain was found in immunoglobulins from normal subjects. Spontaneous degradation of the normal H-chains sometimes yielded fragments of 30,000 mol. wt. These fragments were easily distinguishable from abnormal L-chains. The nature of extra mol. wt in heavy L-chains was investigated for the presence of carbohydrate moiety. Four large and three normal size L-chains were examined for amino-sugar and sialic acid content. A small amount (one residue per molecule) of amino-sugar was detected only in two normal and two heavy L-chains, whereas sialic acid was only found in the heaviest (27,000-30,000) L-chains (Lh) and in small percentage (one or two residues per molecule). Total sugar estimation in one Lh chain indicated a proportion not exceeding three or four residues per L-chain (mol. wt 1,000) and this is insufficient to explain the 15-25% (3,600-6,000) mol. wt increase. It is therefore possible that, at least in some heavy myeloma L-chains, an additional peptide is expressed. Whatever the nature of the increase it would be of interest to elucidate whether this is a marker of malignant process or of an intermediate step of normal Ig synthesis.     

β Chain deficiency in three patients with dysfunctional C8 molecules

Structural and functional studies were performed on a dysfunctional C8 molecule present in the serum of two siblings and an unrelated individual. The C8 in these three sera exhibited a pattern of partial immunologic identity with C8 in normal serum but was devoid of functional activity. The C8 was immunoprecipitated from the three sera and from a control serum with an antihuman C8 antiserum and analyzed by SDS-PAGE using highly purified human C8 as a reference. A selective absence of a band of 62,000 mol. wt was observed in the immunoprecipitates from the sera containing dysfunctional C8. Experiments performed with the purified α-γ and γ subunits showed that the hemolytic activity of the C8 deficient sera could be reconstituted by the addition of the β chain but not the α-γ dimer. Binding of the dysfunctional C8 to C$\text{567}$ was excluded by the following observations: (1) EAC 1–7 treated with the C8 deficient sera and then washed could not be lysed after the addition of the β subunit and C9; and (2) the abnormal molecules did not interfere with the consumption of normal C8 by the soluble complex SC5b-7.     

阴道内放置PGE_2用于足月妊娠引产351例疗效观察

目的　比较 PGE2 阴道栓剂及催产素静滴引产的效果。方法　将 5 85例同样条件孕妇 ,随机分两组 ,分别给PGE2 阴道栓剂和催产素静脉滴注引产。结果　前列腺素组及催产素组引产成功率分别为 96 .3%和 79.92 % ;临产发动时间及总产程分别为 (2 .70± 0 .6 3) h,(3.0 1± 3.41) h和 (3.91± 0 .71) h,(6 .0 3± 3.5 0 ) h;剖宫产率分别为6 .8%和 18.18% (P<0 .0 1) ,有显著差异。结论　 PGE2 栓剂用于足月妊娠引产效果显著、安全、方便 ,对促宫颈成熟意义重要 ,可缩短住院天数 ,减少住院费用。     

硒对大鼠肝细胞DNA损伤的体内体外研究

应用单细胞凝胶电泳研究了一定剂量的亚硒酸钠对离体和在体大鼠肝细胞 DNA损伤的作用。结果表明 :在2 .185、 4.375、 8.75 0、 17.5 0 0、 35 .0 0 0 μmol/ L 的剂量条件下 ,除 2 .185 μmol/ L 的剂量外 ,其余剂量的亚硒酸钠均可引起离体大鼠肝细胞 DNA损伤。 5、 10、 2 0 μmol/ kg的亚硒酸钠也可引起在体大鼠肝细胞 DNA损伤。亚硒酸钠引起的离体和在体大鼠肝细胞 DNA损伤均存在明显的剂量 -反应关系。研究结果提示 ,一定剂量的亚硒酸钠能引起离体和在体大鼠肝细胞 DNA损伤     

三氧化二砷对肝癌细胞系HepG2生长及核基质蛋白的影响

目的 探讨三氧化二砷对人肝癌细胞系ＨｅｐＧ２的生长及核基质蛋白的影响。方法 应用生长指数分析和高分辨ＳＤＳ－聚丙烯酰胺交双向电泳比较用Ａｓ２Ｏ３处理后的ＨｅｐＧ２细胞主核基质蛋白的改变。结果 Ａｓ２Ｏ３抑制ＨｅｐＧ２的生长,双向电泳显示经Ａｓ２Ｏ３处理后ＨｅｐＧ２细胞内出现新的核基质蛋白,并且该蛋白是细胞特异性的。结论 核基质蛋白是某些抗癌药物的作用靶子,Ａｓ２Ｏ３抑帛 癌细胞的生长可望有用于临床     

定向克隆构建RAB5A基因真核细胞表达载体

目的 探讨ＲＡＢ５Ａ作为蛋白质人胞信号传导调控者在肿瘤转移中的作用及影响。方法 采用双酶切、定向克隆技术建立了人ＲＡＢ５Ａ基因真核细胞表达载体ｐｃＤＮＡ３．１（－）０ＲＡＢ５Ａ。结果 测定分析证实了ＲＡＢ５Ａ基因正向插入ｐｃＤＮＡ３．１（－表达载体,免疫组化分析表明转染了ｐｃＤＮＡ３．１（－）－ＲＡＢ５Ａ表达载体的ＡＧＺＹ８３－ａ细胞系细胞内的荧光亮度明显强于转染前,蛋白电泳显示近２３ＫＤ的蛋白质     

新生儿脐血血液流变学观察

目的 :观察新生儿脐血的血液粘度、血浆粘度、红细胞压积、血沉、红细胞电泳情况。方法 :新生儿分娩断脐后立即抽取脐血 4ml+肝素抗凝 ,并立即送检 ,采用北京普利生 L BY- N6 A自清洗旋转式粘度计检验。结果 :母体为正常生理妊娠的新生儿组 :全血低切粘度 8.91± 6 .79m pa· s,全血高切粘度 5 .6 6± 2 .0 mpa· s,血浆粘度 1 .46± 0 .2 4m pa· s,红细胞压积 5 0 .1±1 8.4% ,血沉 2 .1 4± 1 .36 mm/ h,红细胞电泳 1 5 .82± 3.79s;母体为妊高征的新生儿组 :全血低切粘度 1 1 .96± 7.38m pa· s,全血高切粘度 6 .48± 1 .5 7mpa· s,血浆粘度 2 .5 3± 1 6 .4mpa· s,红细胞压积 31 .47± 0 .35 % ,血沉 1 .6 8± 1 .43mm/ h,红细胞电泳1 5 .6 8± 3.43s;正常妇女组 :全血低切粘度 2 2 .33± 6 .88mpa· s,全血高切粘度 4.5 0± 0 .5 4mpa· s,血浆粘度 1 .73± 0 .0 9mpa· s,红细胞压积 41 .0 9± 2 .6 0 % ,血沉 1 7.0 9± 6 .35 mm/ h,红细胞电泳 2 1 .0 4± 1 .44 s。结论 :孕期母体血液流变学变化对新生儿影响较小     

Nerve-induced release of nitric oxide in the rabbit gastrointestinal tract as measured by in vivo microdialysis

1. Nitric oxide (NO) has been suggested as a gastrointestinal neurotransmitter, mediating the gastric receptive relaxation and the relaxation in the peristaltic reflex. The aim of the present study was to measure nerve-induced NO formation in vivo in the gastrointestinal tract.
2. Formation of the nitric oxide oxidation products nitrite and nitrate during vagal nerve stimulation were measured in the anaesthetized rabbit. Microdialysis probes were inserted into the wall of the stomach and proximal colon, and nitrite and nitrate in dialysate measured by capillary electrophoresis.
3. During bilateral vagal nerve stimulation there was an increase in nitrite and nitrate formation at the level of the stomach and in nitrite formation at the level of the colon. This increase was inhibited by intravenous administration of the NO synthase inhibitor N^ω-nitro-L-arginine methyl ester (L-NAME 30 mg kg⁻¹). Furthermore, L-NAME significantly increased nerve-induced gastric and colonic contractions, as well as spontaneous colonic contractions.
4. In summary, we present a new methodological procedure for quantification of small changes in nitric oxide formation in vivo. This study provides evidence that nitric oxide is released in the stomach and colonic wall during vagal nerve activity, at concentrations able to cause inhibition of smooth muscle contractions in vivo.

     

琼脂糖火箭电泳法测定唾液溶菌酶活性

本文采用琼脂糖火箭电泳法测定唾液溶菌酶活性,将琼脂扩散方法和电泳技术结合一起,使溶菌酶在电场中泳动,在通过含有作用底物的凝胶时与溶壁微球菌发生水解作用,形成可见的溶菌透明峰,根据峰值与溶菌酶浓度的时数值成正比的关系求得样品溶菌酶含量。该方法简便、快速、稳定性好,灵敏度高,结果准确可靠。在本实验条件下最低检出量为1.25 μg/ml,在5.O-100.0μg/ml范围内呈良好的浓度-峰高的线性关系,r=O.9947,P<0.001,批内重复变异系数CV=4.15％,批间重复变异系数CV=7.42％,平均回收率为95％～114％。     

血清尿酸的毛细管电泳测定

目的用毛细管电泳中的胶束动电法直接测定血清尿酸浓度。方法以ＳＤＳ作为电泳缓冲液中和胶束相,采用非涂渍毛细管２１ｃｍ×５０μｍ（ｉ．ｄ．）,检测波长２３５ｎｍ,以外标法定量。结果尿酸测定的线性范围为４６．５～１５００μｍｏｌ／Ｌ,最低检测限为２０．３１μｍｏｌ／Ｌ：本法的日内和日间变异系数均小于４．５％;平均回收率为１０１．４５％。内生性化合物和临床某些常用药物对此方法无干扰。结论该法线性范围宽,简单、快速,可应用于临床样品检测。