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Summary FABPs in the various tissues play an important role in the intracellular fatty acid transport and metabolism. Reye's syndrome (RS) and multisystemic lipid storage (MLS) are human disorders characterized by a disturbance of lipid metabolism of unknown etiology. We investigated for the first time L-FABP in these two conditions. Affinity purified antibodies against chicken L-FABP were raised in rabbits, and found to cross-react specifically with partially purified human L-FABP. L-FABP content in liver samples of two patients with RS and MLS was investigated by immuno-histochemistry, SDS-PAGE and ELISA. L-FABP immuno-histochemistry showed increased reactivity in the liver of RS patient and normal reactivity in MLS liver. L-FABP increase in RS liver was confirmed by densitometry of SDS-PAGE and ELISA method. By these two methods the increase amounted to 180% and 199% (p < 0.02), respectively, as compared to controls. A possible role of L-FABP in the pathogenesis of RS is discussed.  相似文献   
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This research tested the utility of two classes of skin secretion compounds to the phylogeny of the Bufo crucifer group. Skin secretions from specimens of nine populations of B. crucifer group were obtained and submitted to qualitative analysis. We observed a clear difference in the composition of the skin secretion molecules obtained from the species of Bufo studied. Fifty-nine molecules, 16 indolealkylamines and 43 proteins, were used as characters, and 39 of these were parsimonious informative. The tree topology of the skin secretion combined data showed areas of congruence and conflict when compared to an mtDNA phylogeny of the B. crucifer group. We used the Templeton test to evaluate the heterogeneity between the skin secretion and mtDNA data. Although not recommended, we performed a combined analysis with the two partitions. The skin secretion characters from the species of Bufo studied have phylogenetic signal. These data are indicative, at least as a preliminary study, of the phylogenetic relationships among the B. crucifer group taxa.  相似文献   
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Insular mammalian populations living in areas of small size are often characterized by a drastic change in body mass compared to related continental populations or species. Generally, small mammals (less than 100 g) evolve into giant forms while large mammals (up to 100 g) evolve into dwarf forms. These changes, coupled with changes in other life, behavioural, physiological or demographic traits are referred to generally as the insular syndrome. We tested in this study the relative contribution of three factors — area of island, numbers of competitor species and number of predator species — to changes in body size of the woodmouse (Apodemus sylvaticus) in the Western Mediterranean Sea. Our results, based on a comparative analysis using the phylogenetic independent contrasts method, indicate that the increase in body size is related both to the decrease of island size and to the lower number of predator species. A decrease of competitor species does not seem to have an important effect.  相似文献   
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Abstract.  1. Sexuals of a leaf-cutting ant, Atta bisphaerica Forel, left their nest for nuptial flights in October to December.
2. When leaving a nest, 53 of the 479 winged sexuals (or alates) observed (11.1%) carried up to three inquiline spiders of Attacobius luederwaldti .
3. Spiders exclusively selected winged sexuals, not workers, and preferred females, indicating their expectation of the stronger flight ability of females. Neither these sexuals nor workers that appeared out of the nest on flight days attempted to remove or attack spiders on the body of alates.
4. New qucens landing from their nuptial flight did not carry spiders, indicating that the spiders had left the ants in the sky to be dispersed by wind.
5. No spiders were found in more than 100 incipient nests, which were estimated to be 2–3 months old. This suggests that the spiders jumped off the alate during mid-flight and dispersed on the wind to inhabit larger nests.  相似文献   
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Diphtheria toxin fragment A interacts with Cibacron blue in solution, although it is not retained by blue Sepharose columns. Difference spectral titration of fragment A with the dye gives a dissociation constant of the order of 10–5 M and a 11 stoichiometry for the complex. In equilibrium dialysis experiments Cibacron blue behaves as a competitive inhibitor of the binding of NAD to diphtheria toxin fragment A. The dye inhibits in a non-competitive way the fragment A-catalysed transfer of ADP-ribose from NAD to elongation factor 2 (EF2). By affinity chromatography on blue Sepharose a binding of EF2 and of ADP-ribosyl-EF2 with the dye is also demonstrated. GDP, GTP and GDP(CH2)P are able to displace EF2 from blue Sepharose.  相似文献   
8.
Purified lentil seedling amino oxidase (LSAO) is homogeneous in the analytical ultracentrifuge, but shows heterogeneity in gel-filtration HPLC and in PAGE. Two components were obtained from HPLC and PAGE, but at least 6-7 subforms were seen by electrofocusing techniques. The chromatographic and electrophoretic forms are not interconvertible, indicating the presence of covalent differences. The electrophoretic pattern, but not the chromatographic pattern, is modified by treating the enzyme with a pool of glycohydrolases. The copper-free enzyme shows the same type of heterogeneity as the native enzyme, this ruling out the possibility that some subforms were due to the presence of apoenzyme.  相似文献   
9.
DNA methylase extracted with low salt from mouse Krebs II ascites cell nuclei has been degraded stepwise by trypsin treatment. Degradation, accompanied by a limited reduction in size of the native enzyme, leads to the progressive introduction of several nicks so that, eventually, fragments of 14, 18, 24 and 28 kD are released on denaturation. This illustrates the domain structure of the enzyme. In contrast to ascites cell nuclear extracts, preparations from liver nuclei are already nicked and the major from of the enzyme contains a 100 kD fragment though the native molecular weight is unchanged. Newborn mouse liver contains more undegraded enzyme that is mostly firmly-bound within the nucleus. Trypsin treatment increases the de novo activity of the enzyme and prevents its aggregation in the absence of salt, even in the presence of high concentrations of native DNA.  相似文献   
10.
Captopril has been reported to inhibit ouabain-sensitive Na+/K+-ATPase activity in erythrocyte membrane fragments. We investigated the effect of captopril on two physiological measures of Na+/K+ pump activity: 22Na+ efflux from human erythrocytes and K+-induced relaxation of rat tail artery segments. Captopril inhibited 22Na+ efflux from erythrocytes in a concentration-dependent fashion, with 50% inhibition of total 22Na+ efflux at a concentration of 4.8 X 10(-3) M. The inhibition produced by captopril (5 X 10(-3) M) and ouabain (10(-4) M) was not greater than that produced by ouabain alone (65.3 vs. 66.9%, respectively), and captopril inhibited 50% of ouabain-sensitive 22Na+ efflux at a concentration of 2.0 X 10(-3) M. Inhibition by captopril of ouabain-sensitive 22Na efflux was not explained by changes in intracellular sodium concentration, inhibition of angiotensin-converting enzyme or a sulfhydryl effect. Utilizing rat tail arteries pre-contracted with norepinephrine (NE) or serotonin (5HT) in K+-free solutions, we demonstrated dose-related inhibition of K+-induced relaxation by captopril (10(-6) to 10(-4) M). Concentrations above 10(-4) M did not significantly inhibit K+-induced relaxation but did decrease contractile responses to NE, although not to 5HT. Inhibition of K+-induced relaxation by captopril was not affected by saralasin, teprotide or indomethacin. We conclude that captopril can inhibit membrane Na+/K+-ATPase in intact red blood cells and vascular smooth muscle cells. The mechanism of pump suppression is uncertain, but inhibition of ATPase should be considered when high concentrations of captopril are employed in physiological studies.  相似文献   
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