Oligosaccharide-Related Epitope Specific for a Brain-Specific Glycoprotein, 1D4 Antigen

The characteristics of glycosylation of a brain-specific glycoprotein, 1D4 antigen, and the epitope recognized by its monoclonal antibody were studied. Removal of high-mannose and hybrid types of N-linked oligosaccharides by treatment with endoglycosidase H converted the molecular mass of the 1D4 antigen from 89 kDa to 78 kDa, but did not affect its reactivity with the 1D4 monoclonal antibody. Removal of all types of N-linked oligosaccharides by treatment with glycopeptidase F or removal of both N- and O-linked oligosaccharides by chemical treatment caused both reduction of the molecular mass of the antigen to 63 kDa and loss of its reactivity with the monoclonal antibody. These results suggest that the 1D4 monoclonal antibody recognizes a complex-type oligosaccharide-related epitope specific for the 1D4 antigen. Results also showed that N-linked glycosylation was not responsible for the charge heterogeneity of the 1D4 antigen. The oligosaccharide chain-related epitope was detected in rat brain but not in mouse, rabbit, or bovine brain, but the 1D4 antigen was recognized in rat and mouse brains with antiserum (polyclonal antibodies). These findings indicate that the oligosaccharide-related epitope is species specific. Furthermore, results with neuraminidase-treated 1D4 antigen indicated that sialic acids were not involved in the oligosaccharide-related epitope. These findings suggest that the 1D4 antigen may have the oligosaccharide structure specific for rat brain and itself.     

Gastric erosions induced by intracisternal thyrotropin-releasing hormone (TRH) in rats

Intracisternal injection of TRH (1 microgram) under light ether anesthesia induced within 4 hr gastric lesions in 24-hr fasted rats maintained unrestrained at room temperature. Saline, ovine corticotropin-releasing factor (oCRF, 10 micrograms), or human pancreatic growth hormone-releasing factor [hpGRF(1-40), 10 micrograms] tested under the same conditions did not modify the integrity of the gastric mucosa. TRH injected intravenously (100 micrograms/kg) proved to be ineffective. The production of gastric erosions elicited by intracisternal TRH (0.1-1 microgram) or by a stabilized TRH analog, RX 77368 [pGlu-His-(3,3'-dimethyl)-ProNH2, (0.01-0.1 microgram)] was dose-dependent. RX 77368 shows an enhanced potency over TRH. TRH action on gastric mucosa was reversed by atropine, omeprazole and cimetidine. These results demonstrate that TRH, unlike the other hypothalamic releasing factors CRF or GRF, is able to act within the brain to cause the formation of gastric erosions probably through mechanisms involving changes in gastric acid secretion. Intracisternal injection of TRH or its potent analog RX 77368 appears also as a new, simple method to produce centrally mediated experimental gastric erosions in 24 hr-fasted rats.     

用细胞培养的流行性乙型脑炎病毒抗原做ELISA检测特异的IgG抗体

用C6/36细胞增殖流行性乙型脑炎(乙脑)病毒制备抗原,用ELISA法检测乙脑IgG抗体,可获得满意结果。用此法检测了河南,海南地区不同年龄人群的253份血清标本,阳性检出率为55.6％(141/253)。与血凝抑制法(HI)相比较,HI的阳性率仅37.1％(93/253)。两种方法的抗体滴度呈正相关r=0.88。用ELISA检测,乙脑抗体与登革病毒抗原有一定交叉,但滴度平均有16倍差异。本方法重复性良好,具有特异、敏感、简便的特点。可用于乙脑的诊断、流行病学调查和疫苗效果的考核。     

乙型肝炎病毒adr亚型NC-1毒株表面抗原基因的顺序测定与结构研究

用内引物法自pHBVNC-1质粒DNA经Sau3A1降解的1.3Kb片段中,快速、连续测定了HBV adr NC-1表面抗原基因全顺序,与其它三株adr亚型S基因比较,顺序同源性为99％,与adw及ayw亚型比较,同源性为94％。不同亚型间的错义突变比同一亚型不同毒株间的错义突变多。比较11株adr亚型、2抹adw亚型与2株ayw亚型的S基因全顺序,发现在第47,110,113,126,160位的密码子在r亚型中有同源性,在w亚型中也有同源性,所以是w/r亚型决定簇的候选部位。第46,68,134,159,168位的密码子在d亚型中有同源性,而在y亚型中也有同源性,所以是d/y亚型抗原决定簇的候选部位。     

Cholinergic Surface Antigen Chol-1 Is Present in a Subclass of VIP-Containing Rat Cortical Synaptosomes

The colocalization of vasoactive intestinal polypeptide (VIP) with the cholinergic specific surface antigen Chol-1 was investigated in synaptosomes derived from the rat cerebral cortex. Immunoaffinity purification of cortical synaptosomes using antisera to Chol-1 resulted in the copurification of VIP and cholinergic nerve terminals. VIP was purified with a yield of 75% of that of choline acetyltransferase (ChAT). These results suggest that approximately 53% of the cortical cholinergic terminals contain VIP, whereas 75% of the cortical VIP content is present in these cholinergic terminals. Both hypotonic lysis and depolarization of the nerve terminals resulted in the differential release of VIP and acetylcholine (ACh), indicating the different compartmentalization in the same nerve terminal. Complement-mediated lysis of cholinergic nerve terminals, using antisera to Chol-1, resulted in the release of 64% of the ChAT, 71% of ACh, and 27% of the VIP. The application of our method enables quantifying and mapping, with a fast, efficient, and specific technique, the coexisting peptides in cholinergic neurons of distinct brain areas.     

Enhancement of tumor cell susceptibility to lymphokine-activated killer cells by treatment with the streptococcal preparation OK432

We investigated whether tumor cell lysis by LAK cells was augmented by treatment with OK432in vitro. NK and LAK activity against K562 cells was not enhanced by their treatment with OK432. In contrast, the susceptibility of OK432-treated Daudi and KATO-III cells to lysis by LAK cells was enhanced. Succinate dehydrogenase activity and RNA synthesis were impaired in Daudi and KATO-III cells by treatment with OK432, and moreover the expression of HLA Class I antigen and ₂-microglobulin was inhibited in OK432-treated KATO-III cells. Thus, it is suggested that the enhancement of the susceptibility of OK432-treated tumor cells with regard to succinate dehydrogenase activity, RNA synthesis, and HLA Class I antigen expression.     

Chromosome assignments of the genes for glucocorticoid receptor,myelin basic protein,leukocyte common antigen,and TRPM2 in the rat

We have utilized rat-mouse somatic cell hybrids to make chromosomal assignments for the glucocorticoid receptor (GR), myelin basic protein (MBP), leukocyte common antigen (LCA), and testosterone-repressed prostate message-2 (TRPM2) genes in the rat. The genes for GR and MBP both map on chromosome 18 of the rat, which corresponds to the mapping of both genes on chromosome 18 of the mouse. The gene for LCA maps on chromosome 13, which is where C4b-binding protein -chain (C4BPB), coagulation factor V (F5), and renin have previously been assigned. This linkage group appears to be homologous to a substantial portion of mouse chromosome 1 and human chromosome 1q. Finally, the TRPM2 gene has been assigned to rat chromosome 15.This project was supported by Grants RG 1877-A-1 from the National Multiple Sclerosis Society and P50 DE09164 from the NIH, by grants from the Swedish Cancer Society, the Erik Philip-Sörensen Foundation, the Trygger Foundation, the IngaBritt and Arne Lundberg Research Foundation, CANCIRCO, and BioVast (Gothenbrug), by the Belgian program on Interuniversity Attraction Poles initiated by the Belgian State-Prime Minister's Office-Science Policy Programming, and by a grant from the CGER-ASLK (Brussels). C.S. is a Senior Research Associate of the National Fund for Scientific Research (FNRS, Belgium).     

Analyses of ribosomal proteins from mycobacteria with particular reference to the β antigen

Abstract The proteins of the ribosomal subunits of Mycobacterium phlei were analysed by sodium dodecylsulphate (SDS)-polyacrylamide gel electrophoresis (PAGE) and by 2-dimensional PAGE. These techniques revealed that both the size and the charge of the mycobacterial ribosomal proteins were quite different from those of Escherichia coli . The divergent chemical properties of the mycobacterial ribosomes might be related to other exceptional properties of mycobacteria, e.g., their slow growth. An antigen designated β was furthermore revealed in both 30S and 50S subunits of M. phlei and Mycobacterium bovis BCG. 2 Proteins from each subunit migrated in a similar way in SDS-PAGE, being thus prime candidates as carriers of β-activity.     

The effect of antibodies to the enterobacterial common antigen (ECA) on experimental mouse salmonellosis

Abstract The protective capacity of antibodies to the enterobacterial common antigen (ECA) was tested in experimental mouse salmonellosis after intraperitoneal challenge by moderately virulent smooth Salmonella typhimurium . No evidence could be found for a role of anti-ECA in protection or opsonization in assays in which homologous anti- Salmonella antiserum was strongly positive.     

Expression of hepatitis B virus surface antigen P31 gene in Escherichia coli

A hepatitis B virus surface antigen (HBsAg) P31-coding DNA was constructed from a DNA fragment of the plasmid pHBr330 containing the entire hepatitis B virus (HBV) adr DNA and a chemically synthesized adaptor. The P31 gene was inserted into an expression vector, pTRP771, having an Escherichia coli tryptophan operon (trp) promoter to give a recombinant plasmid pTRP P31-R. The distance between the Shine-Dalgarno (SD) sequence and the initiation codon of P31 gene was adjusted to 9 bp. The expression level of HBsAg by E. coli 294[pTRP P31-R] was significantly elevated, in contrast to that of HBsAg by E. coli 294[pTRP SS-6]. Western blotting analysis has shown that E. coli[pTRP P31-R] synthesizes a specific polypeptide P31 of about 31 kDal, which reacts with anti-HBsAg antibody. The binding studies with polyalbumins from various species have also suggested that HBsAg P31 specifically binds to polymerized human serum albumin.