A rapid method for determination of Proteus vulgaris with a piezoelectric quartz crystal sensor coated with a thin liquid film

A rapid method for microorganism detection using a piezoelectric quartz crystal sensor (PQC) coated with a thin liquid culture medium film was developed and applied to detect the cell number of Proteus vulgaris. This method employed the viscosity and density response of PQC and utilized the coagulation of gelatine medium solution in which the microorganisms had grown to determine the microorganism indirectly. Three time points (TT₁, DT, TT₂) were obtained from the coagulation curve and were found to be in good linear relationship with the logarithm of the initial number of P. vulgaris in the range 1·3 × 10²−1·3 × 10⁵ cells/ml. The detection was rapid and accurate because the coagulation of the thin liquid culture medium film was quick and the time points in the response curve were sharp and so were easy to determine accurately. The detection time was less than 4 h and only a micro sample was needed. A 5 h preincubation was needed before detection. Some experimental conditions are discussed in detail.     

中国土厉螨属一新种（蜱螨亚纲：厉螨科）

本文记述中国土厉螨属１新种,王氏土厉螨Ｏｌｏｌａｅｌｅｐｓｗａｎｇｉ,ｓｐ．ｎｏｖ,新种的模式标本保存在宁夏回族自治区地方病防治所。     

油麻藤凝集素的荧光光谱研究

用化学修饰、内源荧光和荧光淬灭等方法研究了油麻藤凝集素（ＭＳＬ）的溶液构象变化和微环境的构象特征。研究发现ＭＳＬ分子中总共有９个色氨酸（Ｔｒｐ）残基,它们的荧光能被丙烯酰胺淬灭,但不易为ＫＩ接近而淬灭,ＭＳＬ经Ｎ－溴代琥珀酰亚胺（ＮＢＳ）修饰后,其内源性荧光发射谱发生相应变化,结果表明ＭＳＬ分子中部分Ｔｒｐ残基埋藏于分子内部,而位于分子表面的Ｔｒｐ残基可能处于分子的疏水袋中。     

水稻巯基蛋白酶抑制剂的分子修饰与其对稻瘟病菌的抑制作用

水稻巯基蛋白酶抑制剂（ＣＰＩ）经用二硫苏糖醇,对氯汞苯甲酸和碘乙酸修饰后,对木瓜蛋白酶的抑制活性并无改变;用Ｎ－乙基顺丁烯二酰亚胺与ＣＰＩ反应,可以测出ＣＰＩ分子内有１９个巯基被修饰,被修饰后,抑制活性仍无改变,表明水稻ＣＰＩ的抑制活性不需要巯基参与;应用Ｎ－溴代丁二酰亚胺与ＣＰＩ反应,可测出ＣＰＩ分子内有２个Ｔｒｐ被修饰,修饰后,抑制活性全部丧失,表明Ｔｒｐ是保持抑制活性所必需的基团。水稻巯基蛋白酶抑制剂和丝氨酸蛋白酶抑制剂对稻瘟病菌丝体的生长均有抑制作用,但后者的抑制作用比前者更强,若将两种抑制剂混合使用,则对稻瘟病菌丝体的抑制作用非常强烈;当抑制剂加入量达７２μｇ时,即可产生明显的抑制作用。     

黄精凝集素Ⅱ分子稳定性与生物学活性研究

黄精凝集素Ⅱ分子稳定性与生物学活性研究鲍锦库,曾仲奎,周红（四川大学生物系,成都,６１００６４）本文在黄精凝集素Ⅱ纯化及性质研究的基础上,应用多种变性条件,研究其分子特性,同时对分子的巯基和色氨酸进行修饰,研究该凝集素分子保持其生物学活性与这些基团的...     

河南新乡地区儿童头面部测量

本文对河南省新乡地区汉族儿童（４－１３岁）头面部进行了测量,比较和分析了儿童体质发育与年龄增长的关系,据儿童头面部各指数数值大小分型,确定该地区汉族儿童面部的形态为：圆头型、高头型、狭头型、狭面型、狭鼻型。     

药用野生稻GBSS基因的系统发育及组织特异性表达

淀粉作为主要的碳水化合物在储藏能量方面发挥至关重要的作用。颗粒结合型淀粉合酶(GBSS)与直链淀粉的合成息息相关。尽管该酶的编码基因已在许多栽培植物中被分离和确定, 但有关它们在作物野生近缘种中的序列分歧和表达的研究却相对较少。该研究以药用野生稻(Oryza officinalis)为研究对象, 定性和定量地分析了GBSS编码基因的序列特点、与其它植物同源基因的进化关系以及在叶和种子中的表达情况。系统发育分析表明, 该酶在禾本科植物中分别由GBSSI和GBSSII基因编码。在药用野生稻中, 这2种基因所编码蛋白的氨基酸序列一致性为62%, 并且它们在不同器官内呈现时空分化表达, 其中GBSSI在种子中超强表达, GBSSII则主要在叶片表达。     

Self-splicing of the Chlamydomonas chloroplast psbA introns.

We used alpha-32P-GTP labeling of total RNA preparations to identify self-splicing group I introns in Chlamydomonas. Several RNAs become labeled with alpha-32P-GTP, a subset of which is not seen with RNA from a mutant that lacks both copies of the psbA gene. Hybridization of the GTP-labeled RNAs to chloroplast DNA indicates that they originate from the psbA and rrn 23S genes, respectively, the only genes known to contain group I introns in this organism. Introns 1, 2, and 3 of psbA (with flanking exon sequences) were subcloned and transcribed in vitro. The synthetic RNAs were found to self-splice; splicing required Mg2+, GTP, and elevated temperature. In addition, the accuracy of self-splicing was confirmed for introns 1 and 2, and intermediates in the splicing reactions were detected. These results, together with our recent data on the 23S intron, indicate that the ability to self-splice is a general feature of Chlamydomonas group I introns. These findings have significant implications for the mechanism of group I intron splicing and evolution in Chlamydomonas and other chloroplast genomes.     

LBL, a novel, developmentally regulated, laminin-binding lectin.

A 190/220-kDa complex found in integrin preparations was purified, and monoclonal antibodies were raised against it. The immunoaffinity-purified complex appears to be a trimer of very similar or identical 70-kDa subunits. It is a novel extracellular matrix molecule as determined by its subunit composition, N-terminal amino acid sequence, and in vivo localization. It is distributed widely in basement membranes including those from muscle, nerve, and kidney. It is also present in connective tissue regions such as perineurium and perimysium. It has the unusual property that it is initially expressed very late in avian development near the time of hatching. This protein is found to copurified with integrin because it binds to the carbohydrate support in Sepharose. Hemagglutination assays with mono- and disaccharides show that it functions as a lectin with galactoside-binding specificity. This protein is also found to bind strongly and specifically to laminin at a site distinct from its lectin activity, but does not bind to fibronectin or type IV collagen. The protein appears to be conserved and is a common contaminant of many laminin preparations. We call this novel protein "LBL" for laminin-binding lectin.     

Structural diversity in the extracellular faces of peptidergic G-protein-coupled receptors. Molecular cloning of the mouse C5a anaphylatoxin receptor.

The mouse C5a receptor gene was isolated using the human C5a receptor cDNA probe recently described (Gerard, N. P., and C. Gerard. 1991. Nature 349:614). By analogy with the human gene, the mouse homolog contains two exons with the 5' untranslated region and initiating methionine codon present in exon 1 and the remainder of the molecule in exon 2. Generation of an expressible cDNA for the mouse C5a receptor was accomplished using the polymerase chain reaction and a sense oligodeoxynucleotide primer which included an initiation codon just 5' to the sequence encoding the N-linked glycosylation site. When transfected into human 293 kidney epithelial cells the cloned cDNA directs expression of a binding site for human C5a anaphylatoxin with a binding constant of 2.5 +/- 0.3 nM; the human C5a receptor expressed under identical conditions has a Kd of 1.7 +/- 0.2 nM. Overall, the deduced amino acid sequences of the receptors are 65% identical given the analogous gene structures. Alignment of the sequences as seven transmembrane segment receptors reveals that the greatest structural diversity (approximately 70%) exists in the putative extracellular domains. In contrast, species differences among other members of this family of seven membrane-spanning receptors is generally only 10 to 20%, even for receptors whose ligands are relatively small and not expected to interact with sites on the extracellular surfaces. A high degree of structural identify is observed for the C5a receptors in the transmembrane segments and in all but one of the loops predicted to exist in the cytoplasm. Inasmuch as critical structures responsible for high affinity binding of the 74 amino acid polypeptide to both C5a receptors involve features conserved between species, these data provide the starting point for mutagenesis studies to determine the nature of the binding and activation sites for the chemotactic receptors. Additionally, these data provide a reagent for immunologic and molecular genetic studies on the role of C5a receptors in inflammatory models.