Production of monoclonal antibodies against avian LHRH-I

Summary Production of antibodies against peptides or poorly antigenic proteins by conventional methods often requires either large quantities of the native immunogen or some chemical modification to increase their antigenicity. In this study an in vivo and in vitro immunization protocol has been used to generate monoclonal antibodies against the decapeptide luteinizing hormone-releasing hormone (LHRH). Two injections of 100 μg of avian LHRH-I into BALB/c mice were given 7 d apart. Dissociated splenocytes were collected under sterile conditions. They were incubated with 100 μg of the immunogen in 75-cm² tissue culture flasks in thymocyte-conditioned media. After 5 to 8 d exposure to the antigen, splenocytes were fused with SP2/O myeloma cells by polyethylene glycol. The cells were plated into 24 wells and then incubated in hypoxanthine aminopterin and thymidine selective media. After 14 d an initial screening was done by enzyme immunoassay. The positive wells (6/24) were expanded into 96-well plates and rescreened. Selected lines were cloned out 3 times by limiting dilution and the most positive expanded for ascites production. The antibody was affinity purified in a protein A column. The antibody cross-reacted with LHRH-I and II but preferentially to LHRH-I, as shown by competitive assay. A hypothalamic extract from a mature chick showed a higher response than preparations from whole brain explants of 1- to 3-d posthatched chicks, mature quail, and mature mouse. This work was funded by the Maryland Agricultural Experiment Station artical no. A4975, contribution no. 8019.     

伊贝母体细胞无性系的建立及其胚状体的发生

本文报道了伊贝母体细胞无性系的建立及其胚状体的发生。已继代培养三年零六个月共30多代的鳞芽愈伤组织,目前仍有分化能力。通过愈伤组织形态细胞学的观察,发现伊贝母体细胞无性系形成小鳞茎的途径有二:一是由特化了的愈伤组织表皮细胞。经多次分裂发育成不定芽而形成小鳞茎;二是由愈伤组织表层或内层特化了的胚性细胞,经多次分裂发育成胚状体而形成小鳞茎。不定芽和胚状体的形态发生是有区别的。     

糙叶败酱挥发油镇静作用的研究

本文观察了败酱科植物糙叶败酱(Patrinia scabra Bunge)根和根茎中制得的挥发油的镇静作用,井与黄花败酱挥发油做了比较。结果表明,此油灌胃给予数组小鼠,剂量0.45ml/kg,显示如下的作用:[1]能显著延长由于腹腔注射戊巴比妥钠(50mg/kg)引起的小鼠睡眠时间,但其作用强度弱于黄花败酱挥发油。(2)一次灌胃给予小鼠大剂量10.46g/kg的糙叶败酱挥发油,连续观察10天,动物外观正常,无一死亡,体重增加与对照组相似。     

v-mos oncoproteins affect the nuclear retention and reutilization of glucocorticoid receptors

Expression of the p85gag-mos oncoprotein in temperature sensitive transformed 6m2 cells results in desensitization of glucocorticoid induction of metallothionein-1 mRNA. Indirect immunofluorescence analyses demonstrate that hormone insensitivity in v-mos transformed cells is associated with inefficient nuclear retention of glucocorticoid receptor (GR) protein. Desensitized receptors that accumulate in the cytoplasm of transformed 6m2 cells do not regain the capacity for hormone-dependent nuclear translocation after turnover of the thermo-labile p85gag-mos oncoprotein. Although ligand induced down-regulation of immunoreactive GR protein occurs in transformed 6m2 cells, desensitized receptors appear to retain some capacity to bind hormone in vivo. Thus alterations in the intracellular partitioning of GR protein in v-mos-transformed cells result in the generation of a novel desensitized receptor that is apparently trapped in the cytoplasm and incapable of being reutilized.     

大肠杆菌棉子糖操纵子α—半乳糖苷酶表达的调节控制

The alpha-galactosidase, coded for by the first structural gene rafA in the plasmid determined raf operon was an inducible enzyme. In contrast to lac or mel operon, raf operon has more strict structural specificity for inducers. The enzyme can be induced by melibiose and raffinose, or weakly by D-galactose, but not by structurally related sugars such as lactose, PNPG etc.. The alpha-galactosidase forming capacity as function of growth curve reached a single peak at the end of the logarithmic phase of the growth. The structure and regulation of raf operon is similar to those of lac operon. The repressormor-mediated negative control plays a major role in the regulation of raf operon, and cAMP-CAP mediated positive control is also involved in the regulation. When 0.4% glucose was added into the medium with other carbon sources, the expression of the enzyme was repressed by 2-3 fold. Transient catabolite repression has been observed neither in inducible nor constitutive alpha-galactosidase expression. Based on alpha-galactosidase assay, in mutant strains CA8306(cya) and CA8445 (cya, crp) the expression level of raf operon was only 9% and 2.5% of that in wild type strain respectively. The glucose effect or the repression in cya mutant can be abolished by 1-5 mmol cAMP. The constitutive alpha-galactosidase expression in cya and cry double mutant (CA8445) remains repressible by glucose, but irreversible by cAMP, suggesting cAMP-CAP complex is not the exclusive mediator of the catablite repression.(ABSTRACT TRUNCATED AT 250 WORDS)     

记内蒙古Juxia一新种

本文记述了在内蒙古沙拉木伦额尔登敖包地区第三系下渐新统乌兰戈楚组中发现的始巨犀的一个新种:寿氏始巨犀(Juxia shoui)。据其前臼齿及鼻切迹的位置等特点,这一新种当为始巨犀属中比较进步的一个成员,是包氏始巨犀和巨犀之间的过渡类型的犀类动物。     

成人及新生儿颅骨铜和锌含量的初步研究

本文系用原子吸收光谱法测定了西安地区10例成人尸体和15例新生儿尸体的颅盖骨内Cu和zn的含量。结果求得成人颅骨中Cu正常含量(均数±标准差)为4.48±3.78mg/kg(干组织重);zn为597.05±472.54mg/kg。新生儿颅骨中Cu和zn的含量分别为1.96±0.76mg/kg;1160.38±859.71mg/kg。结果表明,成人颅骨内Cu含量高于新生儿,而成人颅骨内Zn含量显著低于新生儿。     

Antinociceptive effects of [D-Ala2]deltorphin II, a highly selective delta agonist in vivo

The present study has characterized the antinociceptive actions of [D-Ala2]deltorphin II following intracerebroventricular (i.c.v.) administration in the mouse tail-flick test. [D-Ala2]deltorphin II produced dose- and time-related antinociception, with maximal effects at +10 min and significant antinociception which lasted for 40-60 min. [D-Ala2]deltorphin II was 13-fold more potent than i.c.v. [D-Pen2, D-Pen5]enkephalin (DPDPE), a second highly selective delta agonist, and approximately equipotent with i.c.v. morphine in producing antinociception. The antinociceptive effects of i.c.v. [D-Ala2]deltorphin II and DPDPE, but not those of morphine, were antagonized by the selective delta antagonist, ICI 174,864. In contrast, pretreatment with the non-equilibrium mu antagonist, beta-funaltrexamine blocked morphine antinociception, but failed to antagonize [D-Ala2]deltorphin II and DPDPE antinociception. These data indicate that [D-Ala2]deltorphin II produced its antinociceptive effects at a supraspinal delta receptor. [D-Ala2]deltorphin II appears to be the most appropriate delta opioid agonist currently available for studies in vivo and support the involvement of delta receptors in supraspinal antinociception.