575 research outputs found
EPITHELIAL CADHERIN RE-EXPRESSION IN METASTATIC BREAST CANCER AS A STRATEGY FOR METASTATIC COLONIZATION OF THE LIVER
Epithelial-cadherin downregulation enables cancer cells to escape from the primary mass; however, E-cadherin has been found to be expressed on metastatic foci, bringing into question the role of this molecule in tumor progression. We define a novel role for the cellular adhesion molecule E-cadherin, in which the protein's re-emergence promotes carcinoma-parenchymal interactions in ectopic sites. Non-metastatic E-cadherin positive MCF7 breast cancer cells form heterotypic cohesions mediated by E-cadherin, and in invasive and metastatic MDA-MB-231 cells, the E-cadherin promoter hypermethylation that prevents endogenous E-cadherin expression is reversed when these cells are cultured with hepatocytes. The function of this re-expression is suggested by the E-cadherin-dependent sustained activation of Erk-MAP kinase and Akt in these breast carcinoma cells. Thus, we propose that E-cadherin expression and subsequent heterocellular interactions direct cell fate decisions that may ultimately enable colonization of a secondary site by an invasive cancer cell
English medium higher education in Hong Kong: linguistic challenges of local and non-local students
This research project involved a mixed-methods study investigating language-related challenges of first-year students at an English Medium Instruction (EMI) university in Hong Kong. The two-phased sequential study employed a questionnaire survey and semi-structured student interviews. The survey and interview findings indicate that first-year students face a number of language-related academic challenges during their first year at an EMI university in writing, reading, speaking, and listening, many of which appear to stem from lower levels of vocabulary knowledge in English, unfamiliarity with academic and technical terminology, and limited exposure to varieties of English. Additionally, the findings suggest that these challenges can vary significantly based on background and first language, relating specifically to three different demographic student groups: local Hong Kong Cantonese-speaking students, Putonghua-speaking mainland Chinese students, and non-Chinese speaking local and international students
Specimen records of Oarisma Scudder 1872 (Lepidoptera: Hesperiidae) in the Oregon State Arthropod Collection, OSU, Corvallis OR.
Label data for 260 specimens of skipperlets are digitally recorded in a DarwinCore compatible occurrence record dataset (attached). Information about the data and metadata is presented as well as the rationale for capturing this particular set of specimen records
Specimen records for North American Lepidoptera (Insecta) in the Oregon State Arthropod Collection. Pyraloidea: Crambidae Latreille 1810 and Pyralidae Linnaeus, 1758
A dataset for North American specimens in the holdings of the Oregon State Arthropod Collection is presented. Details about the metadata an some basic summary of the contents are presented. The dataset itself, in the form of a text file (csv formatting) is provided in the supplemental file materials
Breast carcinoma cells re-express E-cadherin during mesenchymal to epithelial reverting transition
<p>Abstract</p> <p>Background</p> <p>Epithelial to mesenchymal transition (EMT), implicated as a mechanism for tumor dissemination, is marked by loss of E-cadherin, disruption of cell adhesion, and induction of cell motility and invasion. In most intraductal breast carcinomas E-cadherin is regulated epigenetically via methylation of the promoter. E-cadherin expression is therefore dynamic and open to modulation by the microenvironment. In addition, it has been observed that metastatic foci commonly appear more differentiated than the primary tumor, suggesting that cancer cells may further undergo a mesenchymal to epithelial reverting transition (MErT) in the secondary organ environment following the EMT that allows for escape.</p> <p>Results</p> <p>We first examined E-cadherin expression in primary breast tumors and their corresponding metastases to liver, lung and brain and discovered that 62% (10/16) of cases showed increased E-cadherin expression in the metastases compared to the primaries. These observations led to the question of whether the positive metastatic foci arose from expansion of E-cadherin-positive cells or from MErT of originally E-cadherin-negative disseminated cells. Thus, we aimed to determine whether it was possible for the mesenchymal-like MDA-MB-231 breast cancer cells to undergo an MErT through the re-expression of E-cadherin, either through exogenous introduction or induction by the microenvironment. Ectopic expression of full-length E-cadherin in MDA-MB-231 cells resulted in a morphological and functional reversion of the epithelial phenotype, with even just the cytosolic domain of E-cadherin yielding a partial phenotype. Introduction of MDA-MB-231 cells or primary explants into a secondary organ environment simulated by a hepatocyte coculture system induced E-cadherin re-expression through passive loss of methylation of the promoter. Furthermore, detection of E-cadherin-positive metastatic foci following the spontaneous metastasis of MDA-MB-231 cells injected into the mammary fat pad of mice suggests that this re-expression is functional.</p> <p>Conclusions</p> <p>Our clinical observations and experimental data indicate that the secondary organ microenvironment can induce the re-expression of E-cadherin and consequently MErT. This phenotypic change is reflected in altered cell behavior and thus may be a critical step in cell survival at metastatic sites.</p
Specimen records for North American Lepidoptera (Insecta) in the Oregon State Arthropod Collection. Hepialidae Stephens, 1829
A dataset for North American specimens in the holdings of the Oregon State Arthropod Collection is presented. Details about the metadata an some basic summary of the contents are presented. The dataset itself, in the form of a text file (csv formatting) is provided in the supplemental file materials
Influence, Information Overload, and Information Technology in Health Care
We investigate whether information technology can help physicians more efficiently acquire new knowledge in a clinical environment characterized by information overload. Our analysis makes use of data from a randomized trial as well as a theoretical model of the influence that information technology has on the acquisition of new medical knowledge. Although the theoretical framework we develop is conventionally microeconomic, the model highlights the non-market and non-pecuniary influence activities that have been emphasized in the sociological literature on technology diffusion. We report three findings. First, empirical evidence and theoretical reasoning suggests that computer based decision support will speed the diffusion of new medical knowledge when physicians are coping with information overload. Secondly, spillover effects will likely lead to "underinvestment" in this decision support technology. Third, alternative financing strategies common to new information technology, such as the use of marketing dollars to pay for the decision support systems, may lead to undesirable outcomes if physician information overload is sufficiently severe and if there is significant ambiguity in how best to respond to the clinical issues identified by the computer.
Specimen records for North American Lepidoptera (Insecta) in the Oregon State Arthropod Collection. Cossoidea: Cossidae Leach, 1815 and Sessiidae Boisduval, 1828
A dataset for North American specimens in the holdings of the Oregon State Arthropod Collection is presented. Details about the metadata an some basic summary of the contents are presented. The dataset itself, in the form of a text file (csv formatting) is provided in the supplemental file materials
Specimen records for North American Lepidoptera (Insecta) in the Oregon State Arthropod Collection. Lycaenidae Leach, 1815 and Riodinidae Grote, 1895
A dataset for North American specimens in the holdings of the Oregon State Arthropod Collection is presented. Details about the metadata an some basic summary of the contents are presented. The dataset itself, in the form of a text file (csv formatting) is provided in the supplemental file materials
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