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D Wang CR Stockard L Harkins P Lott C Salih K Yuan 《Biotechnic & histochemistry》2013,88(3-4):179-189
Angiogenesis, or neovascularization, is known to play an important role in the neoplastic progression leading to metastasis. CD31 or Factor VIII-related antigen (F VIII RAg) immunohistochemistry is widely used in experimental studies for quantifying tumor neovascularization in immunocompromised animal models implanted with transformed human cell lines. Quantification, however, can be affected by variations in the methodology used to measure vascularization including antibody selection, antigen retrieval (AR) pretreatment, and evaluation techniques. To examine this further, we investigated the microvessel density (MVD) and the intensity of microvascular staining among five different human tumor xenografts and a mouse syngeneic tumor using anti-CD31 and F VIII RAg immunohistochemical staining. Different AR methods also were evaluated. Maximal retrieval of CD31 was achieved using 0.5 M Tris (pH 10) buffer, while maximum retrieval of F VIII RAg was achieved using 0.05% pepsin treatment of tissue sections. For each optimized retrieval condition, anti-CD31 highlighted small vessels better than F VIII RAg. Furthermore, the MVD of CD31 was significantly greater than that of F VIII RAg decorated vessels (p<0.001). The choice of antibody and AR method has a significant affect on immunohistochemical findings when studying angiogenesis. One also must use caution when comparing studies in the literature that use different techniques and reagents. 相似文献
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Danilo Garcia Sebastian Lundstr?m Sven Br?ndstr?m Maria R?stam C. Robert Cloninger Nóra Kerekes Thomas Nilsson Henrik Anckars?ter 《PloS one》2013,8(8)
Background
The Child and Adolescent Twin Study in Sweden (CATSS) is an on-going, large population-based longitudinal twin study. We aimed (1) to investigate the reliability of two different versions (125-items and 238-items) of Cloninger''s Temperament and Character Inventory (TCI) used in the CATSS and the validity of extracting the short version from the long version, (2) to compare these personality dimensions between twins and adolescents from the general population, and (3) to investigate the genetic structure of Cloninger''s model.Method
Reliability and correlation analyses were conducted for both TCI versions, 2,714 CATSS-twins were compared to 631 adolescents from the general population, and the genetic structure was investigated through univariate genetic analyses, using a model-fitting approach with structural equation-modeling techniques based on same-sex twin pairs from the CATSS (423 monozygotic and 408 dizygotic pairs).Results
The TCI scores from the short and long versions showed comparable reliability coefficients and were strongly correlated. Twins scored about half a standard deviation higher in the character scales. Three of the four temperament dimensions (Novelty Seeking, Harm Avoidance, and Persistence) had strong genetic and non-shared environmental effects, while Reward Dependence and the three character dimensions had moderate genetic effects, and both shared and non-shared environmental effects.Conclusions
Twins showed higher scores in character dimensions compared to adolescents from the general population. At least among adolescents there is a shared environmental influence for all of the character dimensions, but only for one of the temperament dimensions (i.e., Reward Dependence). This specific finding regarding the existence of shared environmental factors behind the character dimensions in adolescence, together with earlier findings showing a small shared environmental effects on character among young adults and no shared environmental effects on character among adults, suggest that there is a shift in type of environmental influence from adolescence to adulthood regarding character. 相似文献4.
To test the hypothesis that substrate-induced steric compression between His 57 and Asp 102 at the active site of chymotrypsin can increase the basicity of His 57, we have synthesized thecis- andtrans-isomers of 2-bromo-3-(N-tritylimidazole)-2-propenoic acid and 2-chloro-3-(N-tritylimidazole)-2-propenoic acid and compared selected properties with those ofcis-andtrans-urocanic acids. Thecis-isomers display low field1H NMR signals at 17 ppm in dimethylsulfoxide, similar tocis-urocanic acid; whereas thetrans-isomers do not show strong hydrogen bonds. Increasing the size of the C2 substituent (H < Cl < Br) in thecis-isomers increases the pKaof the imidazolium group from 6.78 for H to 7.81 and 9.10 for Cl and Br, respectively; whereas the pKas of thetransisomers are all 6.0 ± 0.1. The results indicate that thecis-urocanic acid derivatives with large substituents at C2 act as proton sponges in water, and they support the concept that steric compression in the catalytic triad of chymotrypsin can increase the basicity of His 57. 相似文献
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Chris CR Smith Lisa K Snowberg J Gregory Caporaso Rob Knight Daniel I Bolnick 《The ISME journal》2015,9(11):2515-2526
To explain differences in gut microbial communities we must determine how processes regulating microbial community assembly (colonization, persistence) differ among hosts and affect microbiota composition. We surveyed the gut microbiota of threespine stickleback (Gasterosteus aculeatus) from 10 geographically clustered populations and sequenced environmental samples to track potential colonizing microbes and quantify the effects of host environment and genotype. Gut microbiota composition and diversity varied among populations. These among-population differences were associated with multiple covarying ecological variables: habitat type (lake, stream, estuary), lake geomorphology and food- (but not water-) associated microbiota. Fish genotype also covaried with gut microbiota composition; more genetically divergent populations exhibited more divergent gut microbiota. Our results suggest that population level differences in stickleback gut microbiota may depend more on internal sorting processes (host genotype) than on colonization processes (transient environmental effects). 相似文献
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Schilders G Raijmakers R Malmegrim KC Vande Walle L Saelens X Vree Egberts W van Venrooij WJ Vandenabeele P Pruijn GJ 《Arthritis research & therapy》2007,9(1):R12
Recent studies have implicated the dying cell as a potential reservoir of modified autoantigens that might initiate and drive
systemic autoimmunity in susceptible hosts. A number of subunits of the exosome, a complex of 3'→5' exoribonucleases that
functions in a variety of cellular processes, are recognized by the so-called anti-PM/Scl autoantibodies, found predominantly
in patients suffering from an overlap syndrome of myositis and scleroderma. Here we show that one of these subunits, PM/Scl-75,
is cleaved during apoptosis. PM/Scl-75 cleavage is inhibited by several different caspase inhibitors. The analysis of PM/Scl-75
cleavage by recombinant caspase proteins shows that PM/Scl-75 is efficiently cleaved by caspase-1, to a smaller extent by
caspase-8, and relatively inefficiently by caspase-3 and caspase-7. Cleavage of the PM/Scl-75 protein occurs in the C-terminal
part of the protein at Asp369 (IILD369↓G), and at least a fraction of the resulting N-terminal fragments of PM/Scl-75 remains associated with the exosome. Finally,
the implications of PM/Scl-75 cleavage for exosome function and the generation of anti-PM/Scl-75 autoantibodies are discussed. 相似文献
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Multivalent protein-carbohydrate interactions mediate a wide variety of intercellular recognition processes with high selectivity and specificity. Many synthetic multivalent molecules have been designed to mimic and to inhibit these processes. Using carbohydrate functionalized dendrimers, our goal is to devise a system where the binding activity and the degree of protein clustering induced by the glycopolymer can be readily attenuated. In this paper, dendrimers were functionalized with mixtures of mannose, glucose, and galactose. Their association with concanavalin A was studied using precipitation and hemagglutination assays. With less idealized systems where the association was not optimized, mixtures of low- and high-affinity ligands caused smaller than the theoretically determined differences in binding activity, although linear binding trends were observed. When systems were optimized so that high-affinity binding was achieved, then mixing low- and high-affinity ligands on the dendrimer's surface showed a predictable trend for lectin binding. 相似文献
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Peggy CR Godschalk Mathijs P Bergman Raymond FJ Gorkink Guus Simons Nicole van den Braak Albert J Lastovica Hubert P Endtz Henri A Verbrugh Alex van Belkum 《BMC microbiology》2006,6(1):32-13