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31.
Monocyte-specific antibodies are detrimental to bone marrow and renal transplantation. By using human antimonocyte sera we were able to identify two monocyte-specific antigens, human monocyte antigen 1 and 2 (HMA-1 and HMA-2). The presence of HMA-1 and HMA-2 was compared with the presence of several non-HLA antigens. In panel and inhibition studies, HMA-1 corresponded to the previously described non-HLA granulocyte antigen 9a. Absorption studies showed that HMA-1 and 9a were both present on granulocytes and monocytes. The clinical relevance of these antigens is discussed. 相似文献
32.
Changes, during the reproductive cycle, in fat body, hemolymph, and ovarian proteins of the stable fly Stomoxys calcitrans were characterized quantitatively and qualitatively using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Protein content of all three tissues increased after blood feeding. Fat body protein increased first, followed by hemolymph and ovarian proteins. SDS-PAGE failed to identify vitellogenin in both female hemolymph and fat body samples. No single protein or group of proteins predominated at any stage of the reproductive cycle. Comparisons between male and female stable fly hemolymph and fat body proteins failed to detect female-specific proteins. Female-specific proteins, however, were detected in the hemolymph of four other species of Diptera. 相似文献
33.
Some Properties of Thiosulfate-Oxidizing Enzyme from Marine Heterotroph 16B 总被引:3,自引:1,他引:2
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Thiosulfate-oxidizing enzyme has been demonstrated in cell-free extracts of the marine, thiosulfate-oxidizing pseudomonad strain 16B. The enzyme, partially purified by ion-exchange chromatography and calcium phosphate gel treatment, catalyzed the oxidation of thiosulfate to tetrathionate with the concomitant reduction of ferricyanide. Native but not mammalian cytochrome c was also reduced by the enzyme in the presence of thiosulfate. The enzyme was located exclusively in the supernatant of ultracentrifuged cell extracts. The most purified enzyme preparation, like intact cells, exhibited a temperature optimum of 30 to 31°C. However, it exhibited no definite pH optimum. At pH 6.1 to 6.3 and 30°C, the Km for thiosulfate was 1.57 mM. At lower temperatures, the apparent Km for thiosulfate increased, but the apparent maximum velocity remained virtually unchanged. Thiosulfate oxidation in intact cells exhibited an increase in the pH optimum at lower temperatures. The thiosulfate-oxidizing enzyme of marine heterotroph 16B is compared with thiosulfate-oxidizing enzymes from other bacteria, and the effect of temperature on the relationship between pH and thiosulfate oxidation is discussed with reference to the natural habitat of the bacterium. 相似文献
34.
Marvin R. Mark Edward F. Domino Seong S. Han Aurelio Ortiz Benjamin N. Mathews Sandra K. Tait 《Life sciences》1983,33(12):1191-1197
Parasympathetic denervation of the rat parotid gland by avulsion of the auriculotemporal nerve caused a marked and lasting decrease in gland weight. Parasympathectomy did not change the levels of choline in the gland but decreased by 60% the levels of acetylcholine (ACh) ten days after surgery and 65% at 28 days. It is puzzling that relatively high levels of ACh remained after parasympathetic denervation. The presence of additional cholinergic nerves that innervate the gland, or pass through it en route to other structures may account for some of the remaining ACh. Also, Schwann cells from denervated nerves might have contributed to some of the ACh. The existence of an extraneuronal source of ACh is considered. 相似文献
35.
36.
Relationship of the replication and incompatibility genes of an IncFVI haemolysin plasmid with other F-like haemolysin plasmids 总被引:1,自引:0,他引:1
The replication and incompatibility region of the IncFVI plasmid pSU502 has been isolated by in vitro DNA manipulation as part of a 12.6 kb plasmid, denominated pSU503. Plasmid pSU503 was strongly incompatible with its parental plasmid, pSU1, but was fully compatible with the haemolytic plasmids pSU316 (IncFIII/IV), pHly152 (IncI2) and pSU233 (Inc-pSU233). Furthermore, the 6.9 kb EcoRI fragment of pSU503 which carries the replication and incompatibility determinants of pSU1 did not show any detectable homology (less than 70%) with any of the haemolysin-determining plasmids with which it is compatible. Thus, homologous haemolysin determinants have become linked to apparently unrelated replicons. 相似文献
37.
Jon D. Witman Richard A. Cooper 《Journal of experimental marine biology and ecology》1983,73(1):57-79
The population structures of Terebratulina septentrionalis (Couthouy) from exposed upper rock surface and semi-cryptic rock wall habitats at 33 m depth in the Gulf of Maine differ. Over a 3-yr period, population densities were consistently higher in rock wall habitats. Although both populations were dominated by juveniles (1–4 mm shell length), size-frequency distributions constructed from upper rock surface and rock wall populations were significantly different, as a result of a greater frequency of large brachiopods (> 20 mm shell length) in rock wall populations. Prominent modes occurred at 14–15 mm shell length in upper surface populations and at 19–20 mm length in rock wall populations. Recruitment was higher in rock wall habitats where ambient light intensities were significantly lower than on upper rock surfaces. Differences in recruitment are either the result of larval selection for shaded rock walls or differential juvenile mortality between habitats. The larvae of Terebratulina settle on a diverse array of substrata. These include bedrock, sandy polychaete tubes and algae in upper surface habitats and bedrock, calcareous polychaete tubes, and ascidians in rock wall habitats. Individuals attached to polychaete tubes and algae in upper surface habitats do not attain large body size (> 13 mm shell length). It is suggested that these differences in population structure reflect the greater intensity of disturbance in upper surface habitats. For example, the cod, Gadus morhua (Linnaeus), ingests brachiopods attached to algae and polychaete tubes in this habitat. Gastropod predation affects brachiopods in upper surface habitats but not in rock wall habitats. Predation by gastropods and asteroids is not size-specific. These results are consistent with the hypothesis that predation contributed to the decline in the abundance and diversity of articulate brachiopods since the Mesozoic, and suggest that the restriction of recent populations to semi-cryptic rock wall and crevice habitats is, in part, controlled by disturbance. 相似文献
38.
Differential recognition of the serologically defined HLA-A2 antigen by allogeneic cytotoxic T cells 总被引:2,自引:1,他引:1
A comprehensive analysis of human alloimmune cytotoxic T lymphocytes (CTLs) specific for the HLA-A2 antigen identified 11% of HLA-A2 positive cells as outliers. In total, 11 unrelated serologically indistinguishable, but distinguishable by cell-mediated lympholysis (CML) HLA-A2 positive outlier cells were identified. The outlier cells could be subdivided in two subgroups according to reactivity patterns obtained with CTLs directed against the HLA-A2 antigen of outlier cells and their inhibitory capacity in specific competitive inhibition experiments. Thus, the serologically defined HLA-A2 specificity can be divided into at least three subtypes using CTLs specific for the HLA-A2 antigen. Moreover, CTLs specific for an HLA-A2 subtype could be induced when responder cells expressed a different HLA-A2 subtype antigen. On the basis of several family studies, we conclude that the subtype HLA-A2 antigens are inherited in a codominant way. 相似文献
39.
Raif G. Vasilov Alfred Hahn Horst Mölders Jon J. van Rood Martijn Breuning Hidde L. Ploegh 《Immunogenetics》1983,17(4):333-356
Class I antigens were isolated by immunoprecipitation from cell extracts prepared from mitogenically stimulated and internally radiolabeled peripheral blood lymphocytes (PLBs). The precipitating antibodies used are monomorphic and recognize a determinant on the heavy chain of HLA-A, B, C antigens regardless of their allelic specificities when complexed with
2m, or determinants on
2m itself. Comparison of class I molecules isolated from 25 different homozygous typing cels (HTC) and analyzed by two-dimensional (2-D) gel electrophoresis allowed the identification of those HLA-A,13 locus specificities most common in the European Caucasoid population. Class I antigens isolated from HTC that are HLA identical are biochemically indistinguishable also. Evidence was obtained for the expression of additional class I antigens besides the HLA-A, B, C locus products: for some haplotypes, up to six class I genes may be active in mitogenically activated PBLs. No differences in molecular weight and isoelectric point of the class I heavy chains were observed between the antigens recognized by W6/32, the anti-heavy chain reagent, and anti-
2m reagents. The nature of the mitogenic stimulus, i. e., pokeweed mitogen or phytohemagglutinin, was irrelevant with respect to the class I antigens isolated by this method. Using the HTCs as reference, a panel of HLA-B27 positive heterozygous cells was analyzed. Two types of HLA-B27 antigens, distinct by CML typing were represented. These two forms differed also in their biochemical properties. In addition, we obtained evidence for the existence of an A2 variant. This finding was likewise confirmed by CML typing. 相似文献
40.