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751.
Coordinate Variation in Density and Recombination Potential in T4 Phage Particles Produced at Different Times after Infection 总被引:1,自引:1,他引:0
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Gisela Mosig 《Genetics》1963,48(9):1195-1200
752.
von Banchet GS Richter J Hückel M Rose C Bräuer R Schaible HG 《Arthritis research & therapy》2007,9(1):R6
Innervation of the joint with thinly myelinated and unmyelinated sensory nerve fibres is crucial for the occurrence of joint
pain. During inflammation in the joint, sensory fibres show changes in the expression of receptors that are important for
the activation and sensitization of the neurones and the generation of joint pain. We recently reported that both neurokinin
1 receptors and bradykinin 2 receptors are upregulated in dorsal root ganglion (DRG) neurones (the cell bodies of sensory
fibres) in the course of acute and chronic antigen-induced arthritis in the rat. In this study, we begin to address mechanisms
of the interaction between fibroblast-like synovial (FLS) cells and sensory neurones by establishing a co-culture system of
FLS cells and DRG neurones. The proportion of DRG neurones expressing neurokinin 1 receptor-like immunoreactivity was not
altered in the co-culture with FLS cells from normal joints but was significantly upregulated using FLS cells from knee joints
of rats with antigen-induced arthritis. The proportion of DRG neurones expressing bradykinin 2 receptors was slightly upregulated
in the presence of FLS cells from normal joints but upregulation was more pronounced in DRG neurones co-cultured with FLS
cells from acutely inflamed joints. In addition, the expression of the transient receptor potential V1 (TRPV1) receptor, which
is involved in inflammation-evoked thermal hyperalgesia, was mainly upregulated by co-culturing DRG neurones with FLS cells
from chronically inflamed joints. Upregulation of neurokinin 1 receptors but not of bradykinin 2 and TRPV1 receptors was also
observed when only the supernatant of FLS cells from acutely inflamed joint was added to DRG neurones. Addition of indomethacin
to co-cultures inhibited the effect of FLS cells from acutely inflamed joints on neurokinin 1 receptor expression, suggesting
an important role for prostaglandins. Collectively, these data show that FLS cells are able to induce an upregulation of pain-related
receptors in sensory neurones and, thus, they could contribute to the generation of joint pain. Importantly, the influence
of FLS cells on DRG neurones is dependent on their state of activity, and soluble factors as well as direct cellular contacts
are crucial for their interaction with neurones. 相似文献
753.
Boldrini Gabriel Giezi Martn Molinero Glenda Prez Chaca Mara Vernica Ciminari Mara Eugenia Moyano Franco Crdoba Maria Evelyn Pennacchio Gisela Fanelli Mariel lvarez Silvina Mnica Gmez Nidia Noem 《Biometals》2022,35(2):229-244
BioMetals - Cadmium (Cd) is a toxic metal and an important environmental contaminant. We analyzed its effects on oligoelements, oxidative stress, cell death, Hsp expression and the... 相似文献
754.
755.
This work shows the chemical characterization of a dye processing plant effluent that was contributing to the mutagenicity previously detected in the Cristais river, S?o Paulo, Brazil, that had an impact on the quality of the related drinking water. The mutagenic dyes Disperse Blue 373, Disperse Orange 37 and Disperse Violet 93, components of a Black Dye Commercial Product (BDCP) frequently used by the facility, were detected by thin layer chromatography (TLC). The blue and orange dyes were quantified by high performance liquid chromatography (HPLC/DAD) in a raw and treated effluent samples and their contribution to the mutagenicity was calculated based on the potency of each dye for the Salmonella YG1041. In the presence of S9 the Disperse Blue 373 accounted for 2.3% of the mutagenic activity of the raw and 71.5% of the treated effluent. In the absence of S9 the Disperse Blue 373 accounted for 1.3% of the mutagenic activity of the raw and 1.5% of the treated effluent. For the Disperse Orange 37, in the presence of S9, it contributed for 0.5% of the mutagenicity of the raw and 6% of the treated effluent. In the absence of S9; 11.5% and 4.4% of the raw and treated effluent mutagenicity, respectively. The contribution of the Disperse Violet 93 was not evaluated because this compound could not be quantified by HPLC/DAD. Mutagenic and/or carcinogenic aromatic amines were also preliminary detected using gas chromatograph/mass spectrometry in both raw and treated and are probably accounting for part of the observed mutagenicity. The effluent treatment applied by the industry does not seem to remove completely the mutagenic compounds. The Salmonella/microsome assay coupled with TLC analysis seems to be an important tool to monitor the efficiency of azo dye processing plant effluent treatments. 相似文献
756.
The aim of this work was to use citric acid in the sol–gel process to generate an inorganic polymer that allows bacterial
survival for long periods of time and to study the influence of different storage temperatures. We compared gram-negative
Escherichia coli and gram-positive Staphylococcus aureus, immobilized and preserved at different storage temperatures in silica matrices prepared by the method proposed. Immobilized
E. coli and S. aureus in silica matrices were stored in sealed tubes at 20, 4, −20, and −70°C for 4 months during which the number of viable cells
was analyzed. Results show that the immobilization in silica matrices using citric acid, to neutralize the alkalinity of the
silica precursors, makes the technique not only biocompatible but also easier to perform since polymerization does not occur
immediately as it does when hydrochloric acid is utilized. 相似文献
757.
BACKGROUND AND AIMS: The functional morphology of Salvia pratensis flowers was re-investigated, after new insights revealed that pollen dispensing is one of the main functions of the staminal lever. In particular, no detailed information was available regarding the process of pollen transfer and the forces arising between the pollen-bearing thecae and the pollinating bee's body. The assumption was made that these forces play a significant role in pollen dispensing. METHODS: The functional morphology of S. pratensis flowers and the interaction between flowers and bees (Apis mellifera) were studied by reconstructing stress and strains by using qualitative and semi-quantitative theoretical analysis. Flowers were manipulated to study the spatial arrangement of the filament and lever, and of the head and proboscis of the visiting bee inside the tube. Photographs and films of bee visits on flowers were used to analyse the interaction of pollinator and staminal lever. KEY RESULTS: The spoon-shaped lower lever of S. pratensis has a small hole through which a bee introduces its proboscis into the corolla tube. Although mentioned for the first time by Kerner von Marilaun in 1891, presented here is the first drawing and the first photograph showing this interaction in detail. The analysis of the interaction of flower visitor and the lever mechanism revealed that the position of bees on different flowers is spatially very similar. Flower morphology constrains postures of legitimately nectar-probing bees within narrow bounds. A theoretical discussion on structural elements and force progression in the flower allows the principles of lightweight architecture in flower morphology to be recognized. CONCLUSIONS: The staminal lever of S. pratensis is a pollen-dispensing device. It seems to influence the amount of pollen deposited on pollinators by determining the forces arising between the pollinator and the pollen. The relevant forces occur either during the first, dynamic phase or during the second, almost static phase of a flower visit. 相似文献
758.
Brunstein F Hoving S aan de Wiel-Ambagtsheer G de Bruijn EA Guetens G Eggermont AM ten Hagen TL 《Cancer immunology, immunotherapy : CII》2007,56(4):573-580
Histamine (Hi) combined to melphalan in a rat experimental model of isolated limb perfusion (ILP) for lower limb soft tissue
sarcoma, resulted in overall response rates (OR) of 66%. Likewise, ILP with interleukin-2 (IL-2) resulted in OR of 67%, when
combined to melphalan, in the same experimental model. In systemic immunotherapy, the combination of IL-2 and Hi has been
used for solid tumor treatment based on immunomodulatory effects. In this study, we used our well-established ILP experimental
model to evaluate whether the synergistic effect between the two drugs seen in the systemic setting, could further improve
response rates in a loco-regional setting. Histological evaluation was done directly and 24 h after ILP. Melphalan uptake
by tumor and muscle were measured. Hi and IL-2 together, combined to melphalan in the ILP led to OR of only 28%. Histology
of tumors demonstrated partial loss of Hi-induced hemorrhagic effect when IL-2 was present. Melphalan accumulation in the
tumor when both Hi and IL-2 were added (3.1-fold) was very similar to accumulation with Hi only (2.8-fold), or IL-2 only (3.5-fold)
combined to melphalan. In vitro there was no synergy between the drugs. In conclusion there was a negative synergistic effect
between IL-2 and Hi in the regional setting. 相似文献
759.
Fitzner B Brock P Nechutova H Glass A Karopka T Koczan D Thiesen HJ Sparmann G Emmrich J Liebe S Jaster R 《Cellular signalling》2007,19(4):782-790
Pancreatic stellate cells (PSCs) are the main source of extracellular matrix proteins in pancreatic fibrosis, a pathological feature of chronic pancreatitis and pancreatic cancer. Interferon-gamma (IFN-gamma) is an antifibrotic cytokine, but how precisely it exerts its effects on PSCs is largely unknown. Here, we have focussed on the role of STAT1 as well as target genes of IFN-gamma signalling. Our data indicate that IFN-gamma regulates the expression of two autocrine mediators of PSC activation, connective tissue growth factor and endothelin-1, in a transforming growth factor-beta1-antagonistic manner. STAT1 overexpression under the control of a tetracycline-dependent promoter revealed a close correlation between STAT1 expression and activation, the biological effects of IFN-gamma (growth inhibition, induction of apoptosis), and target gene expression. Our data further support the hypothesis that IFN-gamma interferes with stellate cell activation in the pancreas and suggest activated STAT1 as an inductor of a quiescent PSC phenotype. 相似文献
760.
Stomatal conductance in mature deciduous forest trees exposed to elevated CO<Subscript>2</Subscript>
Sonja Gisela Keel Steeve Pepin Sebastian Leuzinger Christian Körner 《Trees - Structure and Function》2007,21(2):261-159
Stomatal conductance (g
s) of mature trees exposed to elevated CO2 concentrations was examined in a diverse deciduous forest stand in NW Switzerland. Measurements of g
s were carried out on upper canopy foliage before noon, over four growing seasons, including an exceptionally dry summer (2003).
Across all species reductions in stomatal conductance were smaller than 25% most likely around 10%, with much variation among
species and trees. Given the large heterogeneity in light conditions within a tree crown, this signal was not statistically
significant, but the responses within species were surprisingly consistent throughout the study period. Except during a severe
drought, stomatal conductance was always lower in trees of Carpinus betulus exposed to elevated CO2 compared to Carpinus trees in ambient air, but the difference was only statistically significant on 2 out of 15 days. In contrast, stomatal responses
in Fagus sylvatica and Quercus petraea varied around zero with no consistent trend in relation to CO2 treatment. During the 2003 drought in the third treatment year, the CO2 effect became reversed in Carpinus, resulting in higher g
s
in trees exposed to elevated CO2 compared to control trees, most likely due to better water supply because of the previous soil water savings. This was supported
by less negative predawn leaf water potential in CO2 enriched Carpinus trees, indicating an improved water status. These findings illustrate (1) smaller than expected CO2-effects on stomata of mature deciduous forest trees, and (2) the possibility of soil moisture feedback on canopy water relations
under elevated CO2.
An erratum to this article can be found at 相似文献