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941.
942.
The immunogenicity and reactogenicity of the Urabe Am 9 mumps virus vaccine strain were studied after the administration of different doses of the vaccine to 197 children ranging in age from seven and a half months to nine years and without a history of mumps. There was no effect of dose on the response in serum neutralizing antibodies in the range of 10(2.9) to 10(4.7) TCID50/dose. In the 90 subjects without detectable serum neutralization antibodies before vaccination seroconversion was obtained in 94.4% after 42 days. Half of a group of 34 seropositive children who were tested also showed a fourfold or greater rise in antibodies. Persistence of vaccine-enhanced haemagluttinin-inhibition (EHI) antibodies was satisfactory as only two of 46 vaccinees followed-up for between 27 and 32 months had undetectable levels of EHI antibodies and the geometric mean titre of vaccine-induced EHI antibodies had only fallen to about one-third by 32 months after vaccination. Although there was serological evidence of a subclinical re-infection in three subjects, to date none of the vaccinees has had clinical mumps indicating that the vaccine confers protection against disease. The vaccine was well tolerated. Furthermore, the majority of the few 'reactions' reported were probably not vaccine-related. It is concluded that the Urabe Am 9 is an acceptable strain for use in live mumps vaccines. 相似文献
943.
Detergent Effects on the Phosphatidylinositol-Specific Phospholipase C in Rat Brain Synaptosomes 总被引:2,自引:1,他引:1
In the presence of Ca2+ (2.5 mM) and using [14C]arachidonoyl phosphatidylinositol (PI) membrane as substrate, phosphatidylinositol-specific phospholipase C (PI-PLC) (EC 3.1.4.10) in rat brain synaptosomes was activated by deoxycholate but not taurocholate. Calcium stimulated enzymic hydrolysis by both detergents, but the stimulatory effect of taurocholate was less than that of deoxycholate. Peak stimulation for deoxycholate was observed at 1 mg/ml, whereas that for taurocholate was 4 mg/ml. When 1 mM EDTA was added to the taurocholate (4 mg/ml) and Ca2+ (3.5 mM) system, synaptosomal PI-PLC activity was greatly stimulated, to almost the same level as the deoxycholate + Ca2+ system. This system required the presence of all three factors, and EGTA could not effectively replace EDTA in the stimulatory action. The detergent-induced hydrolysis of synaptosomal PI by the deoxycholate + Ca2+ and the taurocholate + Ca2+ + EDTA systems was strongly inhibited by divalent metal ions such as Zn2+, Cu2+, Pb2+, and Fe2+, whereas Mg2+ and Ca2+ were ineffective. Nevertheless, only the deoxycholate + Ca2+ system was responsive to enzyme inhibition by membrane-perturbing agents such as lysophospholipids and free fatty acids. The specific requirement for EDTA in the taurocholate system may be due to the release of a pool of inhibitory divalent metal ions from the membranes. 相似文献
944.
The occurrence of GABA in vas deferens, prostate, epididymis, seminal vesicle and testicle of the rat 总被引:1,自引:0,他引:1
The concentration of gamma-aminobutyric acid (GABA) was determined in vas deferens, prostate, epididymis, seminal vesicle and testicle of the adult rat. Among the organs examined, vas deferens was found to be the richest in GABA and the lowest concentration was measured in testicle. Although the GABA levels appear to be 10-50 times lower in the sex organs examined than in the brain tissue, even the low GABA contents are suggestive of a role of this amino acid in the reproductive organs of the male rat. 相似文献
945.
Elastase-type activity of human serum. Its variation in chronic obstructive lung diseases and atherosclerosis 总被引:2,自引:0,他引:2
W Hornebeck J P Potazman H De Cremoux G Bellon L Robert 《Clinical physiology and biochemistry》1983,1(6):285-292
Human serum was found to contain enzyme activities hydrolyzing succinyl trialanine paranitroanilide and 3H-kappa-elastin Sepharose substrates. Both types of activities could be partly abolished by serine active site titrants (phenylmethanesulfonylfluoride, diisopropylphosphorofluoridate) and partly by neutral chelating agents (EDTA; 1-10-phenanthroline). The combination of phenylmethanesulfonylfluoride and EDTA gave a complete inhibition of human serum elastase-type activities indicating the presence of at least two different types of elastases (serine and metalloproteases) in human serum. In nonsmokers, the average serum elastase-type activity on succinyl trialanine paranitroanilide was found equal to 78.1 ng/ml porcine pancreatic elastase equivalents and on 3H-kappa-elastin sepharose beads equal to 688.8 ng/ml. No statistically significant differences were observed in elastase levels in the sera of individuals presenting clinical symptoms of atherosclerosis. The sera of patients suffering from chronic obstructive lung diseases contained, however, higher amounts of elastase-type activities, respectively equal to 237.2 ng/ml on succinyl trialanine paranitroanilide and 1,096 ng/ml on 3H-kappa-elastin Sepharose beads and was quantitatively significant when compared with control subjects. 相似文献
946.
A series of novel compounds in which a 9-acridinyl nucleus is linked to a psoralen nucleus in the 5- or 8-position via polyamines was prepared and examined. Their reversible binding to DNA and their irreversible binding to DNA and DNA cross-linking upon irradiation with UV-A light were examined. It was found that they were all less efficiently photoreactive than 8-methoxypsoralen (8-MOP), both in cross-linking and photobinding to DNA, whereas the ratio between their photobinding and cross-linking was 40-400 times that of 8-MOP. Compounds in which the linker was attached to the 5-position in psoralen showed smaller cross-linking and photobinding efficiencies and larger ratios between photobinding and cross-linking than those of psoralens attached in the 8-position. This strongly indicates that the 9-substituents of the acridines are oriented toward the minor groove. Flow linear dichroism studies showed that the compounds were DNA intercalating with the acridine moiety, whereas the psoralen moiety in no case was clearly intercalating. This conclusion was further supported by viscometry which also strongly indicated monointercalation. 相似文献
947.
948.
Malic enzyme of pigeon liver binds NADPH at four equivalent enzyme sites and binds Mn2+ and malate each at two sets of "tight" and "weak" sites with negative cooperativity [Pry, T. A., & Hsu, R. Y. (1980) Biochemistry 19, 951-962]. Stopped-flow studies on the displacement of NADPH from the malate-enzyme complexes E4-NADPH4, E4-Mn2(2+)-NADPH4, E4-Mn2(2+)-NADPH4-dimalate, and E4-Mn2(2+)-NADPH4-tetramalate by large excess NADP+ or its analogue phosphoadenosine(2')diphospho(5')ribose show that NADPH dissociates from the binary complex rapidly with a first-order rate constant of 427 s-1. Dissociation from the ternary E4-Mn2(2+)-NADPH4 complex containing two tightly bound Mn2+ ions can be described by a single first-order process with a rate constant of 135 s-1, or more satisfactorily by two simultaneous first-order processes attributable to the reactions of Mn2+-deficient (k congruent to 427 s-1) and Mn2+-liganded (k = 96 s-1) subunits. The latter equals twice the maximum steady-state turnover rate of 53.2 + 3.0 s-1 assigned to dissociation of the reduced nucleotide from transient E-Mn2+-NADPH, and this 2:1 ratio strongly supports our proposed "half-of-the-sites" model [Hsu, R. Y., & Pry, T. A. (1980) Biochemistry 19, 962-968]. Dissociation from the E4-Mn2(2+)-NADPH4-dimalate complex (k = 100 s-1) follows only the slower process, suggesting that occupancy of malate at two sites tightens enzyme-bound NADPH on the adjacent sites. Binding of malate at two additional weak sites yields E4-Mn2(2+)-NADPH4-tetramalate and a NADPH dissociation rate constant of 2.69 s-1. The 97% decrease in NADPH dissociation parallels the observed 93% maximal inhibition by malate and is the cause of substrate inhibition.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
949.
Otto D. Hensens Ray S. Dewey Jerrold M. Liesch Mary A. Napier Robert A. Reamer Jack L. Smith Georg Albers-Schönberg Irving H. Goldberg 《Biochemical and biophysical research communications》1983,113(2):538-547
Spectroscopic evidence suggests the presence of a highly strained ether ring (Fig. 1) (possibly an epoxide) in the C12-subunit of the previously determined partial structure (Fig. 2) of the major neocarzinostatin chromophore (NCS-Chrom ) which completes assignment of all the oxygens in the molecule. The main product from mercaptan treatment suggests opening of the ether ring involving the addition of one molecule of mercaptan as well as reduction of the C12-substructure, whereas a parallel two-step reduction occurs on NaBH4 treatment. Both reactions occur with rearrangement of the C12-substructure and the implication for the mechanism of action of NCS-Chrom in DNA strand scission activity is discussed. The evidence suggests a downward revision of the molecular formula for NCS-Chrom as well as minor components and by two protons. 相似文献
950.
Cultured human choriocarcinoma JEG-3 cells secrete an immunosuppressor that inhibits lymphocyte proliferation stimulated by either an antigen or a mitogen. In this study, the immunosuppressive factor was characterized by three methods: ion-exchange and exclusion chromatography, partition in organic solvents, and thin-layer chromatography on silicic acid. This JEG-3 cell factor appeared to be a protein complex of about 150,000–200,000 Da that contained an immunologically active polar lipid. The structural and functional characteristics of JEG-3 cell immunosuppressor are similar if not identical to those of SIF, a suppressor lymphokine derived from T cells. These secretions from transformed trophoblastic cells may correspond to normal placental products or represent a function of malignant cells. 相似文献