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1.
PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4+ and CD8+ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.  相似文献   
2.
Cultured bovine capillary endothelial (BCE) cells produce low levels of collagenolytic activity and significant amounts of the serine protease plasminogen activator (PA). When grown in the presence of nanomolar quantities of the tumor promoter 12-O-tetradecanoyl phorbol-13-acetate (TPA), BCE cells produced 5-15 times more collagenolytic activity and 2-10 times more PA than untreated cells. The enhanced production of these enzymes was dependent on the dose of TPA used, with maximal response at 10(-7) to 10(-8) M. Phorbol didecanoate (PDD), an analog of TPA which is an active tumor promoter, also increased protease production. 4-O-methyl-TPA and 4α-PDD, two analogs of TPA which are inactive as tumor promoters, had no effect on protease production. Increased PA and collagenase activities were detected within 7.5 and 19 h, respectively, after the addition of TPA. The TPA-stimulated BCE cells synthesized a urokinase-type PA and a typical vertebrate collagenase. BCE cells were compared with bovine aortic endothelial (BAE) cells and bovine embryonic skin (BES) fibroblasts with respect to their production of protease in response to TPA. Under normal growth conditions, low levels of collagenolyic activity were detected in the culture fluids from BCE, BAE, and BES cells. BCE cells produced 5-13 times the basal levels of collagenolytic activity in response to TPA, whereas BAE cells and BES fibroblasts showed a minimal response to TPA. Both BCE and BAE cells exhibited relatively high basal levels of PA, the production of which was stimulated approximately threefold by the addition of TPA. The observation that BCE cells and not BAE cells produced high levels of both PA and collagenase activities in response to TPA demonstrates a significant difference between these two types of endothelial cells and suggests that the enhanced detectable activities are a property unique to bovine capillary and microvessel and endothelial cells.  相似文献   
3.
Parafollicular cells (PC) of the sheep thyroid gland are neural crest derivatives that synthesize and release the biogenic amine serotonin (5-HT) as well as the hormone calcitonin. The thyroid also contains a highly specific serotonin-binding protein (SBP). Separation of dissociated thyroid cells was done to study the cellular localization of SBP and to develop a means of isolating PC for study. Various methods were used to obtain an enriched and purified population of PC. Minced thyroid glands were enzymatically dissociated and the cells were layered on a Ficoll linear density gradient. Fractions obtained from the gradient were examined for cell number, viability, 5-HT concentration, SBP activity, and morphology by electron microscopy. One of the fractions was found to be enriched in PC. High levels of 5-HT and SBP were also found in this fraction, whereas these levels were low where the majority of cells were found. This PC-rich fraction, however, contained numerous follicular cells (FC); therefore, additional approaches to cell separation were used. FC can be stimulated in vitro with thyroid stimulating hormone (TSH) to become intensely phagocytic. When stimulated cells were incubated in the presence of silica microspheres, the FC engulfed the microspheres, which were toxic to them. PC did not become phagocytic and were unharmed by the microspheres. Suspended cells, after incubation with microspheres, were centrifuged on a discontinuous gradient, and a PC-rich fraction was obtained. Silica, however, interfered with analysis of SBP. Another method to take advantage of the phagocytic potential of FC was therefore used. TSH-stimulated cell suspensions were passed through a column of sepharose to which thyroglobulin had been coupled. Stimulated FC apparently adhered to the beads and were retained by the columns. Fractions eluting from the columns were greatly enriched with PC. These fractions contained high levels of 5-HT and SBP, and considerably reduced FC contamination was found by quantitative electron microscopy. It is concluded that SBP is localized to PC in the sheep thyroid. The idea that these cells resemble serotonergic neurons in their mechanisms of 5-HT storage is supported.  相似文献   
4.
In a three-hour bioassay, we tested the palatability and feeding preferences of Uresiphita maorialis (kōwhai moth) for Sophora tetraptera, Sophora microphylla and Sophora prostrata. Palatability tests showed no differences among the Sophora species. Feeding preferences, on the other hand, showed that S. tetraptera and S. microphylla leaves are preferred over S. prostrata leaves. Our results support our field observations in Wellington city parks and gardens showing that S. tetraptera and S. microphylla plants frequently have higher densities of larvae than S. prostrata.  相似文献   
5.
The interaction of a number of phenolic compounds, being ‘model fragments’ of humic acids, with cadmium ions was investigated. The fluorescence quenching method was used to determine the complexation constants of these compounds with cadmium ions. It was established that bonding of phenolic compounds by cadmium ions at рН 7 is weak and reaches a maximum value of 15% for interaction with resorcinol. It was demonstrated that modification of humic acids by the mechanoactivation method increases by three times bonding of cadmium ions, which is caused by strengthening the acid properties of carboxyl and hydroxyl groups at the aromatic ring. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
6.
We have recently found that matrix metalloproteinases (MMPs) are targets for T-cell and B-cell reactivity in experimental arthritis. In the present article, we investigate whether modulation of MMP-specific T-cell responses could influence the course of adjuvant arthritis (AA). Lewis rats were treated nasally with MMP peptides prior to or after AA induction. Administration of the MMP-10 or the MMP-16 peptide prior to AA induction reduced the arthritic symptoms. In contrast, administration of the MMP-10 peptide after AA induction aggravated the arthritic symptoms. The present study shows the possible usefulness of MMP peptides for immunotherapy. However, a clear understanding of proper timing of peptide administration is crucial for the development of such therapies.  相似文献   
7.
Effects of medium viscosity on kinetic parameters of poly(U) hydrolysis catalyzed by RNase from Bac. intermedius 7P (binase) were studied in solutions of sucrose (4-50 wt. %) and glycerol (35-62 wt. %) in Tris--sodium acetate buffer (pH 7.5) at 25 degreesC. The rate constant of reaction kcat was practically unchanged over a wide range of viscosities (1-15 cP for sucrose and 2.5-3 cP for glycerol). In glycerol solutions, kcat slightly increased with viscosity increase from 4 to 10 cP. Addition of NaCl to the buffer medium resulted in an inhibitory effect of Na+ on kcat, prevented by 50% sucrose or 60% glycerol. It is concluded that binase-catalyzed poly(U) cleavage occurs through a "tense"-substrate mechanism, similarly to reactions catalyzed by alpha-chymotrypsin, trypsin, and laccase.  相似文献   
8.
Granule-bound starch synthase: structure, function, and phylogenetic utility   总被引:18,自引:2,他引:16  
Interest in the use of low-copy nuclear genes for phylogenetic analyses of plants has grown rapidly, because highly repetitive genes such as those commonly used are limited in number. Furthermore, because low- copy genes are subject to different evolutionary processes than are plastid genes or highly repetitive nuclear markers, they provide a valuable source of independent phylogenetic evidence. The gene for granule-bound starch synthase (GBSSI or waxy) exists in a single copy in nearly all plants examined so far. Our study of GBSSI had three parts: (1) Amino acid sequences were compared across a broad taxonomic range, including grasses, four dicotyledons, and the microbial homologs of GBSSI. Inferred structural information was used to aid in the alignment of these very divergent sequences. The informed alignments highlight amino acids that are conserved across all sequences, and demonstrate that structural motifs can be highly conserved in spite of marked divergence in amino acid sequence. (2) Maximum-likelihood (ML) analyses were used to examine exon sequence evolution throughout grasses. Differences in probabilities among substitution types and marked among-site rate variation contributed to the observed pattern of variation. Of the parameters examined in our set of likelihood models, the inclusion of among-site rate variation following a gamma distribution caused the greatest improvement in likelihood score. (3) We performed cladistic parsimony analyses of GBSSI sequences throughout grasses, within tribes, and within genera to examine the phylogenetic utility of the gene. Introns provide useful information among very closely related species, but quickly become difficult to align among more divergent taxa. Exons are variable enough to provide extensive resolution within the family, but with low bootstrap support. The combined results of amino acid sequence comparisons, maximum-likelihood analyses, and phylogenetic studies underscore factors that might affect phylogenetic reconstruction. In this case, accommodation of the variable rate of evolution among sites might be the first step in maximizing the phylogenetic utility of GBSSI.   相似文献   
9.
10.
Effect of negative air ions on respiratory organs and blood   总被引:1,自引:0,他引:1  
The effect of negatively charged ions on respiratory organs and blood of rats has been studied. It was shown that the inhaling of negative air ions (NAI) for 60 min with a concentration of NAI at the place of location of animals 320-350 000 ions/cm2 activated the secretion of goblet cells without damaging the mucosa of the trachea and changed the spectrum of proteins of bronchopulmonary lavage. It was also found that the spontaneous production of reactive oxygen species (ROS) by cells of nonfractionated blood after the exposure to NAI increased in both males and females; the intensity of ROS generation induced by opsonized zymosan increased only in females. Different sensitivity of the antioxidant enzymes superoxide dismutase and glutathione reductase of blood to NAI in females and males was revealed. These results enable one to consider the effect of NAI as priming and a weak activation of the respiratory organs through the direct action on the mucosa of the primary target organs of the respiratory tract and then on the blood.  相似文献   
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