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K D Pletsity? G T Sukhikh T V Davydova V A Evseev 《Biulleten' eksperimental'no? biologii i meditsiny》1987,104(8):203-204
The experiments on CBA mice and guinea-pigs have shown that oral vitamin D administration suppressed natural killer activity, decreased the number of T lymphocytes in the peripheral blood and prolonged allograft survival. 相似文献
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A novel pentasaccharide from immunostimulant oligosaccharide fraction of buffalo milk. 总被引:7,自引:0,他引:7
R Saksena D Deepak A Khare R Sahai L M Tripathi V M Srivastava 《Biochimica et biophysica acta》1999,1428(2-3):433-445
A processed oligosaccharide mixture of buffalo milk induced significant stimulation of antibody, delayed-type hypersensitivity response to sheep red blood cells in BALB/c mice. This also stimulated non-specific immune response of the animals measured in terms of macrophage migration index. A novel pentasaccharide has been isolated from the oligosaccharide containing fraction having immunostimulant activity of buffalo milk. This compound was isolated by a combination of gel filtration chromatography, silica gel column chromatography of derivatised oligosaccharides while the homogeneity was confirmed by high performance liquid chromatography. The results of structural analyses, i.e. proton nuclear magnetic resonance, fast atom bombardment mass spectrometry, chemical transformations and degradations are consistent with the following structure: GlcNAcbeta(1-->3)Galbeta(1-->4)GlcNAcbeta(1-->3)Gal beta(1-->4)Glc 相似文献
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1. Several vitamin B12 derivatives including descobalt B12 show unusual inversion of their CD signs upon rapid cooling to liquid N2 temperature, although the room temperature CD signs are conserved by a slower cooling to the same temperature. As a possible explanation for this puzzling observation, a micro-environmental birefringence around the chromophore imbedded in an organic glass is proposed. 2. Absorption, fluorescence, phosphorescence, and polarization spectra of descobalt B12 can be correlated with those of porphyrin free bases, as these two molecular systems share many similarites in their electronic structure. 3. Molecular orbital calculations of polarization directions further support the analoby between the spectroscopic characteristics of corrins and porphyrins, and are generally in good agreement with the fluorescence polarization data. 相似文献
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A quantitative analysis of the different types of germ cells present in the seminiferous tubules of vitamin A-deficient-retinoate
maintained rats revealed that the number of pachytene spermatocytes and spermatogonia was greatly reduced in the deficient
rats. Spermatids were virtually absent in the deficient tubules which contained mostly spermatogonia and preleptotene spermatocytes
along with the Sertoli cells. There was no change in the number of Sertoli cells present in the tubules of deficient rats
as compared to that of normal rats. Following supplementation of retinyl acetate to vitamin A-deficient-retinoate maintained
rats, there was an immediate thinning of the germinal epithelium resulting from the sloughing off of the damaged spermatocytes
which were beyond repair. However, after 12 days of vitamin A supplementation fresh batch of pachytene spermatocytes started
appearing while by day 16 round spermatids could be seen.
Analysis of the acid soluble proteins from nuclei on different types of Polyacrylamide gel electrophoretic systems has revealed
that the levels of the testis specific histone variants Hlt, TH2A and TH2B, synthesized predominantly in the pachytene spermatocytes
were greatly reduced in the testes of retinoate maintained rats. Following supplementation of retinyl acetate for either 4
days or 8 days the levels of these histone variants further decreased which correlated with the decrease in the number of
pachytene spermatocytes. However, by day 12 of supplementation onwards, their levels started increasing and reached near normal
levels by day 24 of vitamin A-supplementation 相似文献
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The incudostapedial (IS) joint between the incus and stapes is a synovial joint consisting of joint capsule, cartilage, and
synovial fluid. The mechanical properties of the IS joint directly affect the middle ear transfer function for sound transmission.
However, due to the complexity and small size of the joint, the mechanical properties of the IS joint have not been reported
in the literature. In this paper, we report our current study on mechanical properties of human IS joint using both experimental
measurement and finite element (FE) modeling analysis. Eight IS joint samples with the incus and stapes attached were harvested
from human cadaver temporal bones. Tension, compression, stress relaxation and failure tests were performed on those samples
in a micro-material testing system. An analytical approach with the hyperelastic Ogden model and a 3D FE model of the IS joint
including the cartilage, joint capsule, and synovial fluid were employed to derive mechanical parameters of the IS joint.
The comparison of measurements and modeling results reveals the relationship between the mechanical properties and structure
of the IS joint. 相似文献
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The analysis of expressed genes in the kidney of Japanese flounder, Paralichthys olivaceus, injected with the immunostimulant peptidoglycan. 总被引:1,自引:0,他引:1
Immunostimulants are widely used in aquaculture, but there are few reports on the genes that are expressed by their stimulation. Therefore, in this study, expressed genes in the kidney of Japanese flounder Paralichthys olivaceus injected with the immunostimulant peptidoglycan were analysed. The results of single-pass sequencing of ESTs from 198 clones (AU090255-AU090451, AU090935) from kidney cDNA are presented. Sequences of the cDNA clones were compared with sequences in the GenBank database. One hundred and six clones (53.5%) appeared to be completely unknown and are likely to represent newly described genes, whereas 92 clones (46.5%) were identified based on matches to sequences in the database. The results contain the genes such as alpha globin (AU090287), several ribosomal proteins (AU090-263, 274, 299, 351, 365, 375, 377, 382, 434, 445), heat shock protein 90 (AU090374) and cytochrome oxidase subunit (AU090385). Immune related cDNAs identified from the kidney were immunoglobulin heavy (AU090291) and light chain (AU090352), beta2-microglobulin (AU090280), macrophage inflammatory protein 1-alpha precursor (AU090535), thymosin beta-10 (AU090391), lysozyme (AU090322) and MHC class IIalpha (AU090435). It is possible that expression of macrophage inflammatory protein 1-alpha results in macrophage activation as a consequence of peptidoglycan treatment. 相似文献
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Voegele AF Jerković L Wellenzohn B Eller P Kronenberg F Liedl KR Dieplinger H 《Biochemistry》2002,41(49):14532-14538
Human plasma afamin, the fourth member of the albumin gene family, is shown to be a specific binding protein for vitamin E. A radio ligand-binding assay followed by Scatchard and Hill analysis are used to show that afamin has a binding affinity for both alpha-tocopherol and gamma-tocopherol, two of the most important forms of vitamin E, in vitro. The binding-dissociation constant was determined to be 18 microM, indicating that afamin plays a role as vitamin E carrier in body fluids such as human plasma and follicular fluid under physiological conditions. Additionally, we demonstrate that afamin has multiple binding sites for both alpha- and gamma-tocopherol. Due to the large binding capacity of afamin for vitamin E, it might take over the role of vitamin E transport in body fluids under conditions where the lipoprotein system is not sufficient for vitamin E transport. To confirm the experimental results, we performed homology modeling and docking calculations on the predicted tertiary structure, which showed coincidence between calculated and in vitro results. 相似文献
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Molecules acting as antioxidants capable of scavenging reactive oxygen species (ROS) are of utmost importance in the living cell. Vitamin C is known to be one of these molecules. In this study we have analyzed the reactivity of vitamin C toward the $ \cdot OH $ and $ \cdot OOH $ ROS species, in all acidic, neutral and basic media. In order to do so, density functional theory (DFT) have been used. More concretely, the meta-GGA functional MPW1B95 have been used. Two reaction types have been studied in each case: addition to the ring atoms, and hydrogen/proton abstraction. Our results show that $ \cdot OH $ is the most reactive species, while $ \cdot OOH $ displays low reactivity. In all three media, vitamin C reactions with two hydroxyl radicals show a wide variety of possible products. 相似文献