抗人C1—抑制物单链抗体的构建

由一株抗人Ｃ１－抑物单克隆抗体鼠杂交瘤细胞提取总ＲＮＡ，合成２对与免疫蛋白可变区ＦＲ１和ＦＲ４互补的通用引物，经ＲＴ－ＰＣＲ扩增出抗体的重链可变区和轻链可变区基因。     

Functional mapping of the activity of the R region in the human T-cell leukemia virus type I long terminal repeat to increase gene expression

We previously demonstrated the activity of the R fragment in the long terminal repeat of human T-cell leukemia virus type I for elevation of the level of gene expression. In this study, the fragment was deleted with BAL31 nuclease to determine its functional domain. Series of the shortened R fragments were linked to the simian virus 40 promoter unit, which regulated expression of a reporter gene. Examination with the R fragments deleted from the 5 and 3 ends showed that borders of the functional domain were mapped within nucleotide positions 458 to 473 for the 5 end and nucleotide positions 559 to 594 for the 3 end, respectively. Thus we conclude that a 136-base-pair fragment corresponding to the second half of the R region was sufficient to allow elevation of the level of gene expression.     

抗人CD154单抗轻重链可变区基因克隆与序列分析

目的:克隆抗人CD154抗体轻重链可变区基因,并分析其核苷酸序列,为基因工程抗体的构建奠定基础。方法:从分泌能抑制免疫反应的抗人CD154单克隆抗体杂交瘤细胞株 7E8中提取总RNA,合成cDNA第一链后,经PCR扩增获得抗人CD154单抗轻链可变区 (VL)和重链可变区 (VH)基因,分别克隆入pUC18载体,并进行序列分析。结果:①抗体的轻链可变区基因全长为 341bp,编码113个氨基酸,归属于Ig的Vκ2基因,氨基酸序列分析结果显示轻链可变区含有明确的 4个骨架区和 3个抗原决定簇互补区,在第 2 3位和第 93位氨基酸为半胱氨酸,是与抗体二硫键形成有关的两个特征性氨基酸;②抗体的重链可变区基因全长为 354bp,编码118个氨基酸,归属于小鼠IgVH基因,D、J区基因分别属于DSP2.9和JH2,氨基酸序列分析结果显示,重链可变区含有明确的 4个骨架区和 3个抗原决定簇互补区,在第 2 3和第 97位氨基酸为半胱氨酸,是与抗体二硫键形成有关的两个特征性氨基酸。结论:经核苷酸序列分析证明所克隆的基因分别为抗体的轻、重链可变区基因.     

Subtle translocation (18;21) confirmed by FISH in a patient with Down syndrome

The patient presented with the typical features of Down syndrome: hypotonia, brachycephaly, flattened occiput, bilateral prominent medical epican-thic folds, flat nasal bridge, protruding tongue, low-set dysplastic ears, short broad hands, bilateral clinodactyly and simian crease. The karyotype of this child was originally reported as normal. High-resolution chromosomes revealed extra material on the long arm of chromosome 18. The mother's karyotype showed a reciprocal translocation between the long arm of 18 and the long arm of 21 at band q23 and q22.1, respectively. FISH performed separately with two different 21q cosmid probes gave two signals on the mother's metaphases and three signals on the prob-and. These findings confirmed that the proband is trisomic for the long arm of chromosome 21 at loci D21S65 and D21S19.     

Human placentae membrane receptor for IgG—i. Studies on properties and solubilization of the receptor

Characterization of the human placental membrane receptor for human ¹²⁵I-IgG is described. The receptor bound specifically both monomers and aggregates of human IgG. Human colostral IgA, bovine, sheep, pig, and horse IgG were not bound. No effect of pH in the range 6.6–7.4, ionic strength in the range 0.1–0.5, and temperature between 4 and 45°C on the binding was found. A water-soluble fraction containing the active receptor (glycoprotein fraction-PGP) was obtained from the placental membranes using lithium diiodosalicylate. The solubilized receptor interacted with IgG better at 4°C than at 20°C or 37°C. The results on replacement of monomeric IgG by aggregated IgG, and vice versa, suggest that both monomers and aggregates of human IgG, were bound to the same receptor sites. The apparent association constant for monomeric human IgG was 0.86 ± 0.2 × 10⁷ mole^?1, and 2.0 ± 0.16 × 10¹⁵ IgG molecules were bound per l mg of the membrane protein. Formaldehyde (0.1%), 2-mercaptoethanol (50 mM), and periodate (4 mM) showed no effect on the binding properties of the membrane-bound and on the solubilized receptor, as well. Higher concentrations of periodate (10 mM or 20 mM) decreased the binding of IgG to membranes but showed no effect on the water-soluble receptor. Both the membrane-bound and the solubilized receptor were sensitive to papain. Pronose abolished the receptor activity after prolonged proteolysis only. Neuraminidase did not affect the activity of the receptor. The decrease of the binding activity of the membrane-bound receptor by trypsin and phospholipase C was due to a release of a material containing an active receptor. No effect of trypsin or phospholipase C on the activity of solubilized receptor was observed. The results obtained suggest a protein character of the placental Fc receptor. After electrophoresis of ¹²⁵I-labeled solubilized receptor in polyacrylamide gel in the presence of SDS, 2 major protein peaks with molecular weights of 74,000 and 104,000 and 3 minor peaks with molecular weights of 56,000, 144,000, and 163,000 were found.     

Ribosomal DNA internal transcribed spacer sequences do not support the species status of Ampelomyces quisqualis, a hyperparasite of powdery mildew fungi

Phylogenetic relationships among Ampelomyces isolates, pycnidial hyperparasites and biological control agents of powdery mildews, were inferred from internal transcribed spacer (ITS) sequences of the ribosomal DNA (rDNA). Currently, these hyperparasites are considered to be a single species, A. quisqualis, despite observed morphological and cultural differences. Ten Ampelomyces isolates, representing seven previously defined ITS RFLP groups, were sequenced and analyzed. Sequence-divergence values among isolates belonging to different RFLP groups ranged from 4.3 to 22.4%, suggesting that these isolates may represent different taxa. When Ampelomyces ITS sequences were analyzed by cladistic methods with the sequences of other ascomycetous fungi, they formed two lineages in the Dothideales. Slow-growing Ampelomyces isolates formed a clade with Leptosphaeria microscopica and L. nodorum, whereas fast-growing Ampelomyces isolates formed a clade with Epicoccum nigrum. Sequence-divergence values between these two clades ranged from 17.3 to 22.4%, suggesting that the taxa in the two clades are not closely related and possibly not congeneric. The data presented here indicate that the identification of `A. quisqualis' isolates used in biological control experiments should be re-evaluated. Received: 10 March 1997 / Accepted: 13 February 1998     

Allergic conversion of protective mucosal immunity against nasal bacteria in patients with chronic rhinosinusitis with nasal polyposis

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Comparative study of the prognostic value of nuclear grade and silver-binding nucleolar organizer region in renal cell carcinomas.

Silver-binding nucleolar organizer region (AgNOR) and nuclear grade were histologically assessed in 112 renal cell carcinomas. Nuclear grade was better capable of stratification than AgNOR in terms of survival prediction. It also had prognostic significance when total metastatic rates were evaluated. Although higher mean AgNOR numbers were constantly associated with higher nuclear grades, two arbitrary classifications of AgNOR (less than 1.5, 1.5-3.5, greater than 3.5; less than 2, 2-3, greater than 3) failed to resolve the survival difference.