骨髓瘤细胞免疫球蛋白重链基因可变区的研究

为分析多发性骨髓瘤 (multiplemyeloma,MM )细胞对免疫球蛋白重链基因可变区 (VH)基因家族的取用 ;根据VH 基因突变特点 ,揭示MM细胞的起源。以重链基因可变区 (VH1 VH6 )基因家族特异性引物 ,用PCR法扩增骨髓瘤细胞系CZ 1细胞和 98例MM患者外周血单个核细胞VH 基因片段 ,纯化后的PCR产物和pMD18 T载体连接并转化JM10 9细菌 ,经克隆鉴定后 ,目的DNA片段用末端双脱氧法测定DNA序列 ,和其对应的胚系基因序列比较。结果表明MM细胞对各VH 基因家族的取用顺序为VH3>VH1>VH4 >VH2 >VH5 >VH6 ;MM细胞VH 基因互补决定区 (CDR )氨基酸替换性突变 (R突变 ) /氨基酸静寂性突变 (S突变 )等于 9 6 7,而骨架区 (FR )R/S等于 0 87,而且随着疾病的进展 ,IgVH 基因并不发生进一步的突变。结论是MM前体细胞在进行VDJ基因重排时 ,对VH 基因家族的取用和基因家族相对大小有关 ;MM细胞可能起源于已经发生抗原选择和体细胞突变的B记忆细胞或前浆细胞。     

钙调神经磷酸酶参与心衰患者心肌重构的信号转导

目的：探讨血管紧张素Ⅱ(Ang Ⅱ)介导的钙调神经磷酸酶（CaN）信号通路参与心力衰竭（CHF）患者心肌重塑的机制。方法:选择因瓣膜性心脏病接受二尖瓣置换术的CHF病人39例，正常对照38例(其中8例来自意外伤亡的器官捐献者)。彩色多普勒超声心动图仪检测心脏扩大和心功能参数。放免法检测血浆及心肌组织Ang Ⅱ浓度，免疫沉淀法测心肌组织CaN、活化T细胞核因子(NFAT₃）、锌指转录因子(GATA₄)磷酸化及蛋白表达，RT-PCR检测肌球蛋白重链（β-MHC）mRNA表达。结果:AngⅡ分别与心脏扩大参数呈显著正相关，而与心功能参数呈显著负相关。CHF患者心肌组织CaN蛋白表达、CaN磷酸化、GATA^₄蛋白表达及β-MHC mRNA表达明显高于对照组，随心功能恶化其表达逐渐增加；NFAT₃磷酸化随心功能恶化而减弱。结论：肾素血管紧张素系统（RAS）激活的CaN信号通路在CHF患者心肌重构机制中可能起重要作用。     

人心肌肌凝蛋白重链的制备研究

目的：探讨制备人心肌肌凝蛋白重链（MHC）的方法,为制备其抗体提供抗原。方法：采用改良性制备人心肌MHC,通过SDS-PAGE及Western印迹分析其纯度及抗原特性。结果：①SDS-PAGE显示,纯化的人心肌MHC呈现只有一分子量较大的代表人心肌MHC带的典型图像;②Western印迹显示,200ku处有一典型的感光带。结论：所用的改良法能有效地提取纯化人心肌MHC,可满足制备其抗体的需要。     

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.     

Heparin-induced extracorporal low-density-lipoprotein precipitation (H. E. L. P.) to improve the recovery of hearing in patients with sudden idiopathic hearing loss

The pathogenesis of sudden hearing loss (SHL) is still not well understood. Possible causes include increased blood viscosity, microthrombosis or altered blood flow. Hypercholesterolemia, hyperfibrinogenemia and increased platelet aggregation are frequently observed in patients with SHL. The aim of this study was to investigate whether drastic lowering of plasma cholesterol and fibrinogen by selective extracorporal apheresis could have a beneficial effect on hearing recovery in these patients. Seven patients with SHL were treated with an extracorporal procedure removing fibrinogen and cholesterol from plasma. Six of the seven patients showed an immediate improvement in auditory thresholds following a single treatment of heparin-induced low-density lipoprotein precipitation. These findings indicate for the first time that acute and drastic removal of plasma fibrinogen and low-density lipoproteins may be an effective clinical method for the treatment of patients with SHL. Received: 19 February 1999 / Accepted: 6 May 1999     

LDL-C直接测定法在生化分析仪上的应用

用日本第一化学药品株式会社LDL—C试剂盒在BeckmanCX4型自动生化分析仪上直接测定血清LDL—C含量。方法批内CV 0 37%～ 1 11% ,批间CV为 2 11%～ 3 0 2 % (n =2 0 )。平均回收率为 98 9% ,在 8 10mmol/L浓度范围内呈良好线性关系。TG <5 0 0mmol/L时与聚乙烯硫酸沉淀法 (X1)及Friedewald(X2 )公式计算结果相关良好 ,回归方程分别为Y =0 988X1+0 0 47,r=0 95 1,Y =0 96 1X2 +0 0 5 2 ,r=0 930。LDL—C直接测定法简单、快速 ,用血量少 ,勿需沉淀分离 ,适宜于自动化分析。     

SO_4~(2-)/ZrO_2在重油催化裂化中的应用研究

对 Ｓ Ｏ２－４ ／ Ｚｒ Ｏ２ 超强酸体系作为重油催化裂化助剂进行了研究。结果表明,加入适量的 Ｓ Ｏ２－４ ／ Ｚｒ Ｏ２ 可提高轻质油收率,并能降低催化剂生焦;在工业催化裂化高温水蒸汽流化的条件下, Ｓ Ｏ２－４ ／ Ｚｒ Ｏ２ 超强酸体系中的 Ｂ 酸对重油催化裂化起着至关重要的作用。     

Myopathy and hypertrophic cardiomyopathy with selective lysis of thick filaments

We present a undescribed condition in a girl who died at 8 years of hypertrophic cardiomyopathy. Muscle and endomyocardial biopsies disclosed a selective loss of thick filaments ultrastructurally. In muscle biopsy histochemical abnormalities of myofibrillar AT-Pase were confined to type 1 fibres. Gel electrophoresis of muscle homogenate showed no qualitative abnormalities of slow and fast myosin heavy chains (MHC) and light chains, and the amount of the different myosin isozymes was in agreement with histochemical myofibrillar ATPase findings. The pathogenetic mechanisms have not been elucidated in this case but we suspect an abnormality of the-cardiac MHC gene, the only gene expressed in the heart and in type 1 skeletal muscle fibres.     

红景天提取液精制工艺的考察

目的：优选红景天提取液的精制工艺。方法：采用了醇沉法和絮凝法两种精制方法。结果：壳聚糖絮凝法优于明胶絮凝法。壳聚糖絮凝法与醇沉法比较红帚天苷保留率分别为95．32％，88.15％；固体物保留率分别为59.7％，63．0％。结论：壳聚糖絮凝法的红景天苷保留率明显高于醇沉法，且两种工艺的固体量无显著性差异。