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排序方式: 共有65条查询结果,搜索用时 15 毫秒
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DC Chhieng AR Frost S Niwas H Weiss WE Grizzle S Beeken 《Biotechnic & histochemistry》2013,88(1):25-36
Small biopsy samples are used increasingly to assess the biomarker expression for prognostic information and for monitoring therapeutic responses prior to and during neoadjuvant therapy. The issue of intratumor heterogeneity of expression of biomarkers, however, has raised questions about the validity of the assessment of biomarker expression based on limited tissue samples. We examined immunohistochemically the expression of HER-2neu (p185erbB-2), epidermal growth factor receptor (EGFR), Bcl-2, p53, and proliferating cell nuclear antigen (PCNA) in 30 breast carcinomas using archived, paraffin embedded tissue and determined the extent of intratumor heterogeneity. Each section was divided into four randomly oriented discrete regions, each containing a portion of the infiltrating carcinoma. For each tumor, the entire lesion and four regions were analyzed for the expression of these markers. Scores of both membrane and cytoplasmic staining of HER-2neu and EGFR, scores of cytoplasmic staining of Bcl-2, and scores of nuclear staining of both p53 and PCNA were recorded. The intensity of staining and the proportion of immunostained cells were determined. A semiquantitative immunoscore was calculated by determining the sum of the products of the intensity and corresponding proportion of stained tumor cells. We analyzed both invasive (IDC) and in situ (DCIS) carcinomas. The Wilcoxon signed-rank test was used for paired comparisons between overall and regional immunoscores and between overall and regional percentages of stained cells. Spearman's correlation coefficients were used to assess the level of agreement of overall biomarker expression with each of the regions. Generalized linear models were used to assess overall and pair-wise differences in the absolute values of percent changes between overall and regional expression of biomarkers. For IDCs, there were no statistically significant differences in the expression of the biomarkers in terms of either the percentage of cells staining or the immunoscores when comparing the entire tumor with each region except for the lower EGFR expression of arbitrarily selected region 1 and lower p53 expression of region 1 compared to that of the entire tumor section. For DCIS, there were no statistically significant differences in the expression of the biomarkers between the entire tumor and each region except in PCNA of region 2 compared to that of entire tumor section. Positive correlation of immunoscores was observed between the entire tumor and each region as well as across all four regions for IDC. Similar observations were noted with DCIS except for HER-2neu and PCNA. No statistically significant differences were observed in the absolute values of percent changes of biomarker expression between overall and the four regions for both DCIS and IDC. Therefore, no significant intratumor heterogeneity in the expression of HER-2neu, Bcl-2, and PCNA was observed in IDC. Minor regional variations were observed for EGFR and p53 in IDC. Similarly, no significant regional variation in the expression of markers was observed in DCIS except for PCNA. 相似文献
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ANDREW D. HIGGINSON LEONI DE WERT HANNAH M. ROWLAND MICHAEL P. SPEED GRAEME D. RUXTON 《Biological journal of the Linnean Society. Linnean Society of London》2012,106(1):90-103
Masquerading animals benefit from the difficulty that predators have in differentiating them from the inedible objects, such as twigs, that they resemble. The function of masquerade has been demonstrated, but how it interacts with the life history of organisms has not yet been studied. Here, we report the use of comparative analyses to test hypotheses linking masquerade to life‐history parameters. We constructed a phylogenetic tree of the British species of the lepidoptera families Geometridae and Drepanidae, and compiled life history and coloration data from the literature. We found that masquerade is associated with the exploitation of a greater diversity of host plants whether measured by the number of families or genera. We found a positive relationship between body size and polyphagy among masquerading species, and no relationship among cryptic species. Among those species predominantly found on woody host plants, masquerading species are more likely to overwinter as larvae while cryptic species mostly overwinter as pupae. Polyphenism was associated with multivoltinism in masquerading species but not cryptic species. Taken together, our results show that masquerade must be viewed as a strategy distinct to crypsis and hence may provide insights into the evolution of both defensive strategies. Our study further demonstrates the utility of broad‐scale between‐species comparisons in studying associations between diverse life‐history parameters and sensory aspects of predator‐prey interactions. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 90–103. 相似文献
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JOHN SKELHORN HANNAH M. ROWLAND GRAEME D. RUXTON 《Biological journal of the Linnean Society. Linnean Society of London》2010,99(1):1-8
Many organisms appear to mimic inanimate objects such as twigs, leaves, stones, and bird droppings. Such adaptations are considered to have evolved because their bearers are misidentified as either inedible objects by their predators, or as innocuous objects by their prey. In the past, this phenomenon has been classified by some as Batesian mimicry and by others as crypsis, but now is considered to be conceptually different from both, and has been termed ‘masquerade’. Despite the debate over how to classify masquerade, this phenomenon has received little attention from evolutionary biologists. Here, we discuss the limited empirical evidence supporting the idea that masquerade functions to cause misidentification of organisms, provide a testable definition of masquerade, and suggest how masquerade evolved and under what ecological conditions. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 99 , 1–8. 相似文献
7.
The control of organic matter on microbially mediated iron reduction and arsenic release in shallow alluvial aquifers, Cambodia 总被引:2,自引:1,他引:2
H. A. L. ROWLAND R. L. PEDERICK D. A. POLYA R. D. PANCOST B. E. VAN DONGEN A. G. GAULT D. J. VAUGHAN C. BRYANT B. ANDERSON J. R. LLOYD 《Geobiology》2007,5(3):281-292
Microbes may play a key role in the mobilization of arsenic present in elevated concentrations within the aquifers extensively exploited for irrigation and drinking water in West Bengal, Bangladesh, and in other regions of South-East Asia. Microcosm experiments using Cambodian sediments (which are also representative of other similar reducing aquifers containing arsenic-rich waters) show that arsenic release and iron reduction are microbially mediated and demonstrate that the type of organic matter present, not necessarily the total abundance of organic matter, is important in controlling the rate and magnitude of microbially mediated arsenic release from these aquifer sediments. The possible role of naturally occurring petroleum in stimulating this process is also demonstrated. In addition to acting as an electron donor, certain types of organic matter may accelerate arsenic release by acting as an electron shuttle, indicating a dual role for organic matter in the process. The results also suggest that the fine-grained sediment regions of these aquifers are particularly vulnerable to accelerated arsenic release following the introduction of labile organic carbon. 相似文献
8.
INTRoDUCTIoNlYho1iumrePensL,whiteclover,isaneconomicallyimportantplantspeciesintemperatepastures.Asbrieflyreportedby[1],ithas16pairsofchromosomes(2n=32).Asyet,nodetailedcytologicalexaminationofthisspecies,suchasC-banding,hasbeenrep0rted.Inthelastdecade,thetechnique0fC-bandinghasbeenusedt0examinehighlyrepeatedsequencesinplantchrom0s0mesandhasprovidedausefultoolf0rtheanalysis0fcyt0geneticstructureincr0pplants[2-71.Inplants,thechr0m0s0mall0calizationofhighlyrepeatedDNAsequencesbyinsituhybr… 相似文献
9.
Early evolution of metazoan serine/threonine and tyrosine kinases: identification of selected kinases in marine sponges 总被引:14,自引:1,他引:13
The phylum Porifera (sponges) was the first to diverge from the common
ancestor of the Metazoa. In this study, six cDNAs coding for protein-
serine/threonine kinases (PS/TKs) are presented; they have been isolated
from libraries obtained from the demosponges Geodia cydonium and Suberites
domuncula and from the calcareous sponge Sycon raphanus. Sequence
alignments of the catalytic domains revealed that two major families of
PS/TK, the "conventional" (Ca(2+)-dependent) protein kinase C (PKC), the
cPKC subfamily, as well as the "novel" (Ca(2+)- independent) PKC (nPKC),
form two separate clusters. In each cluster, the sequence from S. raphanus
diverges first. To approach the question about the origin of
protein-tyrosine kinases (PTK), which are found only in Metazoa, we
analyzed two additional PS/TKs which have been cloned from S. domuncula:
the stress-responsive protein kinase (KRSvSD) and the
protein-kinase-C-related kinase (PRKvSD). The construction of the
phylogenetic tree, comprising the eight PS/TKs and the PTK cloned
previously from G. cydonium, revealed that the PTK derived from the branch
including the KRSvSD kinase. These data facilitate the first molecular
approach to elucidate the origin of metazoan PTK within the PS/TK
superfamily.
相似文献
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