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71.
An indirect enzyme-linked immunoadsorption assay (ELISA) was developed for cytochrome c3 using antisera to the cytochromes fromDesulfovibrio africanus Benghazi, Desulfovibrio vulgaris Hildenborough andDesulfovibrio salexigens British Guiana. The ELISA system was used to test for cross-reactions between these antisera and the heterologous antigens. In contrast to previous experiments using the Ouchterlony technique, all of the cytochromes c3 tested exhibited some degree of cross-reaction. Considerable variation was seen in cross-reactions for cytochromes c3 from differing strains ofD. desulfuricans. This observation raises questions about the taxonomic relatedness of these strains. No cross-reaction was seen with eukaryotic cytochrome c or withD. vulgaris cytochrome c553. The data demonstrate that cytochrome c3 is capable of undergoing nonprecipitating cross-reactions, and thus may not be as immunologically unique as was once thought.Abbreviations ELISA
Enzyme-linked immunoadsorption assay 相似文献
72.
Stored and polysomal ribosomes of mouse ova 总被引:2,自引:0,他引:2
RNP particles of ovulated mouse ova, labeled by exposure of growing oocytes to [3H]uridine, were displayed on sucrose gradients. Under standard salt conditions, radioactivity was observed coinciding with liver ribosomal subunits, monomers, and polysomes. The RNA from each region of the gradient was isolated and was found to contain the expected species of labeled 18S and/or 28S ribosomal RNA. Heterogeneous RNP particles were widely distributed in the gradient. From data on RNase sensitivity and resistance to dissociation in high salt, it was estimated that 20–25% of the total ribosomes were in polysomes. No difference in the distribution was observed when ribosomes were labeled in the early or late growth phase of the oocyte. The evidence suggested that the nonpolysomal subunits and monomers were unable to form a high salt-stable complex in the presence of poly(U) and factors for protein synthesis. Thus, the bulk of the ribosomes are inactive in protein synthesis in ovulated ova and are apparently stored for use in embryonic development. 相似文献
73.
A new diol glucoside, 2-β-d-glucopyranosyloxy-2-methylpropanol, the first reported naturally occurring monoglucoside of an aliphatic dihydric alcohol, was isolated from pods of Acacia sieberana var. woodii. Structure elucidation was based on 1 H and 13C NMR spectroscopy, and enzymatic analyses. The compound was hydrolysed very slowly by almond β-glucosidase, but cleaved by a β-glucuronidase enzyme complex from Helix pomatia. 相似文献
74.
In our earlier analysis of intermolecular interactions between collagen molecules, a major concern with the program employed is that it compared numbers of interactions between residues located on edges of defined, identical width and thus would not necessarily compare the same number of residues in each edge. This would be particularly true of some values of θ where well-defined vertical ranking of residues occurs. We have examined ranking of residues in relation to intermolecular edge association between bovine skin [α1(I)]3 model collagen molecules by utilizing two different methods of counting intermolecular interactions between residues. The interaction peaks at θ = 27.69° and 36.00° are absent or relatively less intense in the plots obtained by utilizing radial distances between interacting residues instead of vertical bands of defined width. These studies suggest caution in accepting recently reported analyses of superhelix coiling of the collagen molecule which point to values of 27.69° or 36.00° for the twist of the superhelix. Although intramolecular interactions clearly point to interaction of collagen molecules at D intervals, they are insufficiently restricted in distribution to provide a reliable estimate of the superhelix angle by procedures so far employed. 相似文献
75.
Vitali I. Betaneli Michael V. Ovchinnikov Leon V. Bachinowsky Nikolay K. Kochetkov 《Carbohydrate research》1980,84(2):211-224
The koenigs-Knorr glycosylation of 4,6-O-ethylidene-1,2-O-isopropylidene-3-O-(2,3-O-isopropylidene-α-l-rhamnopyranosyl)-α-d-galactopyranose (3) by 4,6-di-O-acetyl-2,3-O-carbonyl-α-d-mannopyranosyl bromide (10), as well as Helferich glycosylations of 3 by tetra-O-acetyl-α-d-mannopyranosyl and -α-d-glucopyranosyl bromides, proceeded smoothly to give high yields of trisaccharide derivatives (12, 16, and 17). An efficient procedure for the transformation of 12, 16, and 17 into the α-deca-acetates of the respective trisaccharides has been developed. Zemplén de-acetylation then afforded the title trisaccharides in yields of 53, 52, and 62 %, respectively, from 3. A new route to 1,4,6-tri-O-acetyl-2,3-O-carbonyl-α-d-mannopyranose is suggested. 相似文献
76.
Leon R. Kass 《In vitro cellular & developmental biology. Plant》1981,17(12):1091-1099
Summary Modern science, dedicated since its 17th Century origins to the mastery and possession of nature for the relief of man's estate,
is a source of great social change, affecting our opinions, practices, and ways of life. It thus exists necessarily in tension
with law and morality, our institutions of stability and order. This tension between change and permanence, between science
and law or morals, was institutionalized by the American Founders who sought to encourage, under law, the progress in science
and the useful arts, by means of the copyright and patent laws. American science and technology have flourished under the
patent law, an ingenious ethical and social contract between scientists and the polity, through which private right and interest
and public good generally coincide. Nevertheless, this contract has its limitations. Some of these limitations are vividly
seen through the recent Supreme Court decision (in the Chakrabarty case) to permit the patenting of living microorganisms.
Analysis of this case shows why the contract between science and the polity embodied in the Patent Laws may not always serve
the public good and may also be harmful to science itself. Also, permitting ownership of living species shows how close we
have come in our thinking to overstepping the sensible limits of the project for the mastery and possession of nature. 相似文献
77.
Leon M. Rosenson 《Primates; journal of primatology》1977,18(3):579-588
Six lemur mothers of three different species and oneGalago crassicaudatus mother were observed in the presence of their own anesthetized infants. Two of the lemur mothers spent only very brief periods
sitting near their infants and seldom groomed them; the other four spent over half of the infant immobility period in close
proximity to their infants and groomed them frequently. Four lemur mothers groomed the ano-genital region of their infant
at least once. None of the lemur mothers picked up or carried her immobilized infant, as has been reported for some higher
primate mothers, although one lemur mother used her hands to pull the infant toward her ventrum while sitting on the floor.
Five lemur mothers rejected their infants when the infants displayed disoriented behavior while emerging from anesthesia.
The galago mother retrieved her anesthetized infant in her jaws but dropped the infant several times while attempting to groom
it. These results suggest very tentatively that prosimian mothers lack the ability shown by mothers of some higher primate
species to improvise protective ways of behaving toward helpless infants. 相似文献
78.
CARRIER MEDIATED BLOOD-BRAIN BARRIER TRANSPORT OF CHOLINE AND CERTAIN CHOLINE ANALOGS 总被引:24,自引:19,他引:5
Blood-brain barrier (BBB) transport of choline and certain choline analogs was studied in adult and suckling rats, and additionally compared in the paleocortex and neocortex of adult rats. Saturable uptake was characterized by a single kinetic system in all cases examined, and in adult rat forebrains we determined a Km= 442 ± 60 μM and Vmax= 10.0 ± 0.6 nmol min-1 g-1. In 14–15-day-old suckling forebrains a similar Km (= 404 ± 88 μM) but higher Vmax (= 12.5 ± 1.5 nmol min-1 g-1) was determined. When choline uptake was compared in two regions of the forebrain, similar Michaelis-Menten constants were determined but a higher uptake velocity was found in the neocortex (i.e. neocortex Km= 310 ± 103 μM and Vmax= 12.6 ± 2.8 nmol min-1g-1; paleocortex Km= 217 ± 76 μM and Vmax= 7.2 ± 1.5 nmol min-1 g-1). Administration of radiolabelled choline at low (5 μM) and high (100 μM) concentrations, followed by microwave fixation 60 s later and chloroform-methanol-water separations of the homogenized brain did not suggest a relationship between concentration and the appearance of label in lipid or aqueous fractions as observed in another in-vitro study elaborating two-component kinetics of choline uptake. It was observed that 60s after carotid injection 12–14% of the radiolabel in the ipsilateral cortex was found in the chloroform-soluble fraction. Hemicholinium-3 (Ki= 111 μM), dimethylaminoethanol (Ki= 42 μM), tetraethyl ammonium chloride, tetramethyl ammonium chloride, 2-hydroxyethyl triethylammonium iodide, carnitine, normal rat serum, and to a lesser extent lithium and spermidine all inhibited choline uptake in the BBB. Unsubstituted ammonium chloride and imipramine did not inhibit choline uptake. No difference was observed in blood-brain barrier choline uptake of unanesthetised, carotid artery-catheterized animals, and comparable sodium pentobarbital-anesthetized controls. 相似文献
79.
The present study was done to determine if a progesterone receptor is present in rat pituitary. Cytosol was labeled with 3H-progesterone (3HP) or 3H-RS020 (3HR) and subjected to sucrose-glycerol density-gradient centrifugation. Serum progesterone was measured for correlation with progesterone receptor levels. Two 3HP-binding peaks (4S + 6S) were evident in uterine and pituitary cytosols. The 4S peak was eliminated by competition with unlabeled cortisol leaving a single 6S peak (progesterone receptor). Estradiol (E) priming of the male or female rat increased progesterone receptor levels in pituitary cytosol as demonstrated using 3HP and 3HR, and pituitary progesterone receptor bound 3HR with a higher affinity than 3HP. Following adrenalectomy of gonadectomized rats, progesterone receptor levels were increased in pituitary and uterine cytosol of both E-primed and unprimed groups. An inverse relationship was established between serum progesterone and progesterone receptor levels in the uterus and pituitary suggesting that stressinduced adrenal progesterone secretion significantly influences progesterone receptor levels in the rat. These results demonstrate an estrogen-inducible progesterone receptor in the rat pituitary with properties similar to those of the uterine progesterone receptor. 相似文献
80.
Leon V. Backinowsky Nikolay F. Balan Vitali I. Betaneli Nikolay K. Kochetkov 《Carbohydrate research》1982,99(2):189-193
The capsular polysaccharide from Klebsiella type K54, containing both O-formyl and O-acetyl groups, has been investigated by using the techniques of methylation analysis (by gas-liquid chromatography), periodate oxidation-Smith degradation, and both 1H- and 13C-n.m.r. spectroscopy. Degradation of the native polysaccharide with a bacteriophage-induced glucosidase generated a formylated, as well as a formylated and acetylated, tetrasaccharide, whereas similar depolymerization of the deacetylated polysaccharide yielded a single tetrasaccharide; the corresponding, O-acylated octasaccharides were also isolated and characterized. These oligosaccharides, utilized in chemical and spectroscopic studies in order to determine the location of the O-acyl substituents in the repeating sequence, indicated formylation at O-4 of each lateral d-glucosyl group and acetylation at O-2 of alternate l-fucosyl residues. A new structure for the repeating unit in the polysaccharide is proposed. 相似文献