排序方式: 共有43条查询结果,搜索用时 843 毫秒
1.
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
2.
3.
Smith E Redman RA Logg CR Coetzee GA Kasahara N Frenkel B 《The Journal of biological chemistry》2000,275(26):19992-20001
Unique cell cycle control is instituted in confluent osteoblast cultures, driving growth to high density. The postconfluent dividing cells share features with cells that normally exit the cell cycle; p27(kip1) is increased, p21(waf1/cip1) is decreased, free E2F DNA binding activity is reduced, and E2F4 is primarily nuclear. E2F4-p130 becomes the predominant E2F-pocket complex formed on E2F sites, but, unlike the complex that typifies resting cells, cyclin A and CDK2 are also present. Administration of dexamethasone at this, but not earlier stages, results in reduction of cyclin A and CDK2 levels with a parallel decrease in the associated kinase activity, dissociation of cyclin A-CDK2 from the E2F4-p130 complexes, and inhibition of G(1)/S transition. The glucocorticoid-mediated cell cycle attenuation is also accompanied by, but not attributable to, increased p27(kip1) and decreased p21(waf1/cip1) levels. The attenuation of osteoblast growth to high density by dexamethasone is associated with severe impairment of mineralized extracellular matrix formation, unless treatment commences in cultures that have already grown to high density. Both the antimitotic and the antiphenotypic effects are reversible, and both are antagonized by RU486. Thus, glucocorticoids induce premature attenuation of the osteoblast cell cycle, possibly contributing to the osteoporosis induced by these drugs in vivo. 相似文献
4.
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
5.
6.
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
7.
8.
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
Background
Campylobacter jejuni is the predominant cause of antecedent infection in post-infectious neuropathies such as the Guillain-Barré (GBS) and Miller Fisher syndromes (MFS). GBS and MFS are probably induced by molecular mimicry between human gangliosides and bacterial lipo-oligosaccharides (LOS). This study describes a new C. jejuni-specific high-throughput AFLP (htAFLP) approach for detection and identification of DNA polymorphism, in general, and of putative GBS/MFS-markers, in particular. 相似文献9.
CR Taylor 《Biotechnic & histochemistry》2014,89(6):419-423
The traditional microscope, together with the “routine” hematoxylin and eosin (H & E) stain, remains the “gold standard” for diagnosis of cancer and other diseases; remarkably, it and the majority of associated biological stains are more than 150 years old. Immunohistochemistry has added to the repertoire of “stains” available. Because of the need for specific identification and even measurement of “biomarkers,” immunohistochemistry has increased the demand for consistency of performance and interpretation of staining results. Rapid advances in the capabilities of digital imaging hardware and software now offer a realistic route to improved reproducibility, accuracy and quantification by utilizing whole slide digital images for diagnosis, education and research. There also are potential efficiencies in work flow and the promise of powerful new analytical methods; however, there also are challenges with respect to validation of the quality and fidelity of digital images, including the standard H & E stain, so that diagnostic performance by pathologists is not compromised when they rely on whole slide images instead of traditional stained tissues on glass slides. 相似文献
10.
Pedro LC Pinheiro João CR Cardoso Ana S Gomes Juan Fuentes Deborah M Power Adelino VM Canário 《BMC evolutionary biology》2010,10(1):373