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1.
Growth of cell-free subacute sclerosing panencephalitis (SSPE) virus was compared with that of measles virus in three human neural cell lines; neuroblastoma, oligodendroglioma, and glioblastoma. The Edmonston strain of measles virus replicated in these neural cells as efficiently as in Vero cells. In contrast, the growth of the Mantooth strain of SSPE virus was suppressed moderately in neuroblastoma cells and markedly in oligodendroglioma and glioblastoma cells in spite of the induction of apparent cytopathic effects in these cells. Virus adsorption, defective interfering particles, interferon, and temperature sensitivity were not responsible for this low yield of SSPE virus in neural cell lines. Synthesis of viral proteins of SSPE virus was slower than that of measles virus in oligodendroglioma and glioblastoma cells. These results suggest that the slow rate of synthesis of viral proteins may be relevant to the low yield of SSPE virus in neural cells.  相似文献   
2.
The site of hemolytic activity of a toxin isolated from Aspergillus fumigatus designated Asp-hemolysin was determined by photooxidation techniques. The hemolytic activity of this toxin was strongly inhibited by photooxidation with methylene blue, rose bengal, riboflavin, or eosin G as a sensitizer, whereas crystal violet, hematoxylin, naphthol yellow S, bromothymol blue, methyl orange, and cresol red had no effect. pH dependence of the inactivation with methylene blue was observed in the narrow range of pH values from 7.0 to 8.0, like that of the inactivation with rose bengal or riboflavin. The histidine, cysteine, methionine, tryptophan, and tyrosine content of methylene blue-photooxidized Asp-hemolysin was significantly decreased, while other amino acids were not affected. The hemolytic activity of the toxin was lost more slowly than the histidine residue, being maintained at about 50% even at the time when the histidine residue was completely lost after 30 min. Photooxidation of Asp-hemolysin in the presence of rose bengal also caused a decrease in histidine, methionine, and threonine content. These findings suggest that residues of cysteine, methionine, threonine, tryptophan, and/or tyrosine but not histidine may play an important role through stereostructure in the manifestation of the hemolytic activity of Asp-hemolysin.  相似文献   
3.
Replication of X chromosomes in complete moles   总被引:1,自引:0,他引:1  
Summary DNA replication patterns of X chromosomes in complete hydatidiform moles were studied using cultured fibroblasts from three 46,XX moles resulting from duplication of a haploid sperm, and from a 46,XY mole originating from dispermy. Control cultures included skin fibroblasts from an adult woman and a female fetus as well as PB lymphocytes from an adult woman. Cultures were treated with 5-bromodeoxyuridine for the last 2–4h of the S phase, and the chromosome slides prepared were stained by the Hoechst 33258-Giemsa procedure. Each of the three XX moles studied revealed one early-replicating and one late-replicating X chromosomes, while the XY mole revealed one early-replicating X chromosome. DNA replication patterns of molar X chromosomes were similar to those of adult and fetal fibroblasts, but different from those in adult lymphocytes. These findings indicate that DNA replication kinetics of molar fibroblasts are tissue-specific rather than origin- or developmental-stage specific.  相似文献   
4.
5.
Comparative sequence analysis of Escherichia coli ATP-dependent La protease led to the suggestion that Ser679 is the catalytically active enzyme residue. Site-directed mutagenesis Ser679----Ala, investigation of the cells containing the mutant plasmid, and study of the partially purified mutant protein produced results in favour of this suggestion.  相似文献   
6.
A new polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was developed for genetic typing of the mouse Tnfsf6gld mutation. An artificial restriction site was introduced to the mouse Tnfsf6gld mutation by PCR amplification using a modified primer. The three genotypes of the Tnfsf6 locus (Tnfsf6gld/Tnfsf6gld, Tnfsf6gld/+, and +Tnfsf6-gld/+Tnfsf6-gld) could be distinguished clearly and easily. This PCR-RFLP analysis was found to be useful for the identification of the mouse Tnfsf6gld mutation.  相似文献   
7.
The natural chlorinated auxins 4-chloroindole-3-acetic acid(4-Cl-IAA) and its methyl ester (4-Cl-IAA Me ester) were found,in addition to IAA and its Me ester, by gas chromatography-massspectrometry in immature seeds of Vicia amurensis, a Vicieaespecies. In contrast, only non-chlorinated, IAA and IAA Me esterwere present in immature seeds of three Phaseoleae species.These results are further evidence of the wide distributionof 4-Cl-IAA and its Me ester in various Vicieae. (Received October 3, 1986; Accepted December 22, 1986)  相似文献   
8.
The effects of some gangliosides on active uptake of nonmetabolizable alpha-aminoisobutyric acid (AIB) and Na+, K+-ATPase and Ca2+, Mg2+-ATPase activities in superior cervical ganglia (SCG) and nodose ganglia (NG) excised from adult rats were examined during aerobic incubation at 37 degrees C for 2 h. In NG, amino acid uptake was greatly accelerated with the addition of galactosyl-N-acetylgalactosaminyl-[N-acetylneuraminyl]-galactosylgluc osyl ceramide (GM1) (85%) and also with N-acetylgalactosaminyl-[N-acetylneuraminyl]-galactosylglucosyl ceramide (GM2) or [N-acetylneuraminyl]-galactosyl-N-acetylgalactosaminyl-[N-acetyl- neuraminyl]-galactosylglucosyl ceramide (GD1a) (43% each) compared with a nonaddition control at a 5 nM concentration. Under identical conditions, Na+, K+-ATPase activity was strongly stimulated with GM1 (180%) and GD1a (93%), whereas Ca2+, Mg2+-ATPase activity showed no change. In SCG, on the other hand, AIB uptake was apparently inhibited (-27%) by addition of GM1, with a slight decrease in Na+, K+-ATPase but no change in Ca2+, Mg2+-ATPase activity in the tissue. Both asialo-GM1, in which N-acetylneuraminic acid is deficient, and Forssman glycolipid, which is not present in nervous tissue, failed to produce any significant increase in both SCG and NG not only in amino acid uptake, but also in Na+, K+-ATPase activity. A kinetic study of active AIB uptake showed that GM1 ganglioside produced an increase in Km with no change in Vmax in SCG, whereas it caused a decrease in Km with a slight increase in Vmax in NG. Treatment of NG and SCG with neuraminidase from Vibrio cholerae, an enzyme that split off sialic acid from polysialoganglioside, leaving GM1 intact, caused little inhibition of the amino acid uptake.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
9.
The first total synthesis of glycosphingolipids isolated from wheat flour has been achieved in a regio- and stereo-controlled manner.Abbreviations THF tetrahydrofuran - DMF dimethylformamide Part 53 in the series Synthetic Studies on Cell Surface Glycans  相似文献   
10.
Summary A total of 168 autopsy liver extracts from Japanese individuals were examined for the glutathione S-transferase (GST) isozymes by means of starch gel electrophoresis. The gene frequencies of GST1*1, GST1*2, and GST1*0 in Japanese were 0.252, 0.057, and 0.691, respectively. GST1*3 was detected as a rare variant allele. The incidence of GST1 0 in 41 liver biopsy samples from patients suffering from various liver diseases was investigated using polyacrylamide gel isoelectric focusing. The GST1 0 phenotype was found more frequently in livers with hepatitis and carcinoma than in control livers. The isozymes coded by different GST loci were partially purified and characterized to study their biochemical properties. The apparent Km values with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate for the isozymes at the GST1, GST2, GST3, and GST4 loci were 604, 1345, 776 and 591 M, respectively.  相似文献   
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