红细胞生成刺激素(EPO)的纯化

 本文用中空纤维柱超滤浓缩尿,再经离子交换层析、聚焦层析、凝胶过滤和制备型聚丙烯酰胺凝胶电泳(PAGE)-层析等四步从15L再生障碍性贫血患者尿中获得约2mg EPO制品。比活性达10 300U/mg蛋白。该制品在分析型PAGE中呈一条区带。     

急性病毒性肝炎的发病率慢性肝炎患病率和肝病死亡率的研究

1984～1987年,在黑龙江、河北、河南、湖南、上海五个省市城乡10.08855人口中进行急性肝炎发病率、慢性肝炎患病率、与病毒性肝炎有关的肝病死亡率的研究。急性肝炎标化发病率为152.19/10万,主要发生在20～50岁组人群;因无甲肝暴发流行,除上海外各点季节发病率分布均衡。慢性肝炎标化患病率为158.25/10万(诊断标准为6个月前有明确急性肝炎病史,现有明显的临床症状或体征,肝功能异常,故实际慢肝患病率要高于此数字);与病毒性肝炎有关的肝病死亡(包括肝癌)标化率为22.65/10万,其中肝病为 13.14/10万。男性死亡率显著高于女性。     

兔出血症病毒核酸的某些理化性质的研究

本文对我国无锡分离的兔出血症病毒A_2R-3毒株核酸的某些理化性质进行了研究。采用孚尔根染色、二苯胺反应和核酸酶解实验证实病毒核酸为DNA类型。吖啶橙染色、甲醛反应、核酸酶S_1消化和核酸热变性实验表明病毒核酸为单链型。核酸电泳呈单一组分。电境观察显示核酸分子链呈线状,平均长度约为2.15μ。计算分子量约为2.1—2.5×10~6d。核酸碱基组盛为A25.34、T29.37、G23.85、C21.43、(G C)克分子百分比值为45.28。结合以前的报道、我们认为:兔出血症病毒可以归类于细小病毒科。     

Specificity of lung surfactant protein SP-A for both the carbohydrate and the lipid moieties of certain neutral glycolipids.

Binding specificity of the major surfactant protein SP-A from human and dog lung has been investigated. Radiobinding experiments have shown that both proteins bind in a Ca(2+)-dependent manner to galactose, mannose, fucose, and glucose linked to bovine serum albumin. These results are in accord with a previous study in which monosaccharides were linked to agarose (Haagsman, H. P., Hawgood, S., Sargeant, T., Buckley, D., White, R. T., Drickamer, K., and Benson, B. J. (1987) J. Biol. Chem. 262, 13877-13880). Chromatogram overlays in conjunction with in situ liquid secondary ion mass spectrometry (TLC-LSIMS) of several purified glycosphingolipids and neoglycolipids as well as binding assays with glycolipids immobilized on plastic wells, demonstrate recognition of galactose (human and dog SP-A), glucose, and lactose (human SP-A) in association with specific lipids. In addition, the occurrence of several neutral and acidic glycosphingolipids in human and rat extracellular surfactants and rat alveolar type II cells is described. Selected components among the neutral glycolipids are bound by radiolabeled human SP-A; these are identified by TLC-LSIMS as predominantly ceramide mono- and disaccharides (human surfactant) and ceramide tri- and tetrasaccharides (rat surfactant and type II cells). A recombinant carbohydrate recognition domain (CRD) of human SP-A inhibits the binding of human SP-A to galactosyl ceramide and to galactose- and mannose-bovine serum albumin, indicating that the CRD is directly involved in the binding of SP-A to these ligands. These results provide evidence for a novel type of binding specificity for proteins that have Ca(2+)-dependent CRDs and raise the possibility that glycosphingolipids are endogenous ligands for SP-A.     

Karyotypes of Pneumocystis carinii from Korean rats.

Molecular karyotyping was applied to Pneumocystis carinii(Pc) from two strains of experimental rats, Sprague Dawley(SD) and Fisher(F), in Korea. Field inversion gel electrophoresis and contour clamped homogeneous electric field electrophoresis resolved 15 chromosomal bands from the Pc. The size of the bands was estimated 270kb to 684kb from SD rats, and 273kb to 713 kb from F rats. The bands of 283 kb from SD rats and of 273 kb from F rats stained more brightly suggesting duplicated bands. Total number of chromosomes was at least 16, and total genomic size was estimated 7 x 10(6) bp. All of the bands from F rats hybridized to the probe of repeated DNA sequences of Pc and the band of 448 kb size was proved to contain rDNA sequences, but Pc. chromosome bands from SD rats showed no reactions to the probes. The 2 different karyotypes of P. carinii from 2 strains of rats were maintained consistently for 2 years.     

Tegumental ultrastructure of juvenile and adult Echinostoma cinetorchis]

The tegumental ultrastructure of juvenile and adult Echinostoma cinetorchis (Trematoda: Echinostomatidae) was observed by scanning electron microscopy. Three-day (juvenile) and 16-day (adult) worms were harvested from rats (Sprague-Dawley) experimentally fed the metacercariae from the laboratory-infected fresh water snail, Hippeutis cantori. The worms were fixed with 2.5% glutaraldehyde, processed routinely, and observed by an ISI Korea DS-130 scanning electron microscope. The 3-day old juvenile worms were elongated and ventrally curved, with their ventral sucker near the anterior two-fifths of the body. The head crown was bearing 37-38 collar spines arranged in a zigzag pattern. The lips of the oral and ventral suckers had 8 and 5 type II sensory papillae respectively, and between the spines, a few type III papillae were observed. Tongue or spade-shape spines were distributed anteriorly to the ventral sucker, whereas peg-like spines were distributed posteriorly and became sparse toward the posterior body. The spines of the dorsal surface were similar to those of the ventral surface. The 16-day old adults were leaf-like, and their oral and ventral suckers were located very closely. Aspinous head crown, oral and ventral suckers had type II and type III sensory papillae, and numerous type I papillae were distributed on the tegument anterior to the ventral sucker. Scale-like spines, with broad base and round tip, were distributed densely on the tegument anterior to the ventral sucker but they became sparse posteriorly. At the dorsal surface, spines were observed at times only at the anterior body. The results showed that the tegument of E. cinetorchis is similar to that of other echinostomes, but differs in the number and arrangement of collar spines, shape and distribution of tegumenal spines, and type and distribution of sensory papillae.     

温度对干旱、盐胁迫下两种黄芪属种子萌发和幼苗生长的影响

为探讨温度对干旱、盐胁迫下黄芪属种子萌发和幼苗生长特性的影响,以黄芪属蒙古黄芪和扁茎黄芪2种种子为研究对象,纯净水处理为对照组,NaCl、PEG处理为实验组,设置4个渗透势水平(0、-0.1、-0.3、-0.5 MPa),置于5种不同的温度(10、15、20、25、30 ℃)下,每日观察并记录两种种子萌发和幼苗生长情况。结果表明：旱盐胁迫下蒙古黄芪和扁茎黄芪种子萌发最适宜的温度分别为25和20 ℃左右;蒙古黄芪耐高温不耐低温,而扁茎黄芪恰恰相反;但25和20 ℃均适宜两种幼苗生长,包括胚根、胚轴和子叶的生长。蒙古黄芪各处理组(除未发芽的种子)的平均发芽时间都比扁茎黄芪长;NaCl胁迫程度的增加使得两种种子的最终发芽率降低,但蒙古黄芪的耐盐性高于扁茎黄芪;随着PEG胁迫程度的增加,二者的发芽均受到抑制,甚至会出现完全不萌发,但扁茎黄芪的耐旱性高于蒙古黄芪;在相同的渗透势时,尤其是-0.5 MPa,PEG比NaCl对两种种子的影响大;交互胁迫作用下,随着渗透势的增加两种幼苗的鲜重、干重以及胚根、胚轴、子叶的长和宽变化较大;利用Design Expert软件预测发现：温度25 ℃、NaCl渗透势为-0.1 MPa,温度24 ℃、PEG渗透势为-0.04 MPa的处理是蒙古黄芪种子萌发和幼苗生长达到最优化的组合;而扁茎黄芪最优化的组合则为23 ℃下NaCl渗透势为-0.07 MPa的处理,20 ℃下PEG渗透势为-0.13 MPa的处理。     

Glucose biosensor based on electrodeposited platinum nanoparticles and three-dimensional porous chitosan membranes

The chitosan with three-dimensional porous structure greatly increased the effective electrode surface for loading of platinum nanoparticles and promoted efficient electron transfer. The resulting biosensor had a response time (within 5 s) and a linear response from 6 μM to 4.2 mM glucose with a detection limit of 2 μM (S/N = 3). Moreover, the methodology can be applied for the immobilization of other enzymes.