7,472 research outputs found
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Stromal control of oncogenic traits expressed in response to the overexpression of GLI2, a pleiotropic oncogene.
Hedgehog signaling is often activated in tumors, yet it remains unclear how GLI2, a transcription factor activated by this pathway, acts as an oncogene. We show that GLI2 is a pleiotropic oncogene. The overexpression induces genomic instability and blocks differentiation, likely mediated in part by enhanced expression of the stem cell gene SOX2. GLI2 also induces transforming growth factor (TGF)B1-dependent transdifferentiation of foreskin and tongue, but not gingival fibroblasts into myofibroblasts, creating an environment permissive for invasion by keratinocytes, which are in various stages of differentiation having downregulated GLI2. Thus, upregulated GLI2 expression is sufficient to induce a number of the acquired characteristics of tumor cells; however, the stroma, in a tissue-specific manner, determines whether certain GLI2 oncogenic traits are expressed
HCV clearance patterns in saliva and serum of patients with chronic HCV infection under interferon plus ribavirin therapy
This is the peer reviewed version of the article which has been published in final form at Wiley Online Library. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for self-archiving[Abstract] Statements of the problem: Hepatitis C virus (HCV)-RNA is often present in saliva of HCV-infected patients, with plasma viral load being the only known predictable factor. Interferon plus ribavirin therapy yields a sustained reduction in HCV viremia. This study aimed to assess the presence of HCV in saliva and serum specimens from patients undergoing this combination therapy (CT).
Method of study: Paired serum and saliva specimens were collected from 44 chronic HCV-infected patients at basal time, 4 and 12 weeks after CT onset, at the end of treatment and 6 months latter. Serum HCV-RNA levels were determined by the polymerase chain reaction (PCR) Amplicor system. Presence of HCV-RNA in saliva was tested by a highly sensitive non-commercialized nested-PCR.
Results: The HCV-RNA was detected in 26 saliva specimens at basal time (59.1%). In 34.1% of cases, a concordance viral clearance pattern in serum and saliva was observed in both responders (pattern 1a) and non-responders (pattern 1b). In pattern 2 (13.6% of cases), HCV was detected longer during CT in serum than in saliva (pattern 2a) or in saliva than in serum (pattern 2b). In 11.3% of patients, viral clearance was corroborated either in their serum (pattern 3a) or in their saliva (pattern 3b), but not in both fluids. Of the eight primary responders with 1a clearance pattern, seven were sustained responders. None of the patients with 2a clearance pattern was a sustained responder. Of the two primary responders showing the 3b salivary pattern, one had already relapsed in the first 6 months of follow up.
Conclusions: The present results suggest that the monitoring of salivary levels of HCV would be a helpful means of determining sustained antiviral effects of interferon and ribavirin in the treatment of HCV disease
A high-content, multiplexed screen in human breast cancer cells identifies profilin-1 inducers with anti-migratory activities
Profilin-1 (Pfn-1) is a ubiquitously expressed actin-binding protein that is essential for normal cell proliferation and migration. In breast cancer and several other adenocarcinomas, Pfn-1 expression is downregulated when compared to normal tissues. Previous studies from our laboratory have shown that genetically modulating Pfn-1 expression significantly impacts proliferation, migration, and invasion of breast cancer cells in vitro, and mammary tumor growth, dissemination, and metastatic colonization in vivo. Therefore, small molecules that can modulate Pfn-1 expression could have therapeutic potential in the treatment of metastatic breast cancer. The overall goal of this study was to perform a multiplexed phenotypic screen to identify compounds that inhibit cell motility through upregulation of Pfn-1. Screening of a test cassette of 1280 compounds with known biological activities on an Oris™ Pro 384 cell migration platform identified several agents that increased Pfn-1 expression greater than two-fold over vehicle controls and exerted anti-migratory effects in the absence of overt cytotoxicity in MDA-MB-231 human breast cancer cells. Concentration-response confirmation and orthogonal follow-up assays identified two bona fide inducers of Pfn-1, purvalanol and tyrphostin A9, that confirmed in single-cell motility assays and Western blot analyses. SiRNA-mediated knockdown of Pfn-1 abrogated the inhibitory effect of tyrphostin A9 on cell migration, suggesting Pfn-1 is mechanistically linked to tyrphostin A9's anti-migratory activity. The data illustrate the utility of the high-content cell motility assay to discover novel targeted anti-migratory agents by integrating functional phenotypic analyses with target-specific readouts in a single assay platform. © 2014 Joy et al
{\phi}^4 Solitary Waves in a Parabolic Potential: Existence, Stability, and Collisional Dynamics
We explore a {\phi}^4 model with an added external parabolic potential term.
This term dramatically alters the spectral properties of the system. We
identify single and multiple kink solutions and examine their stability
features; importantly, all of the stationary structures turn out to be
unstable. We complement these with a dynamical study of the evolution of a
single kink in the trap, as well as of the scattering of kink and anti-kink
solutions of the model. We see that some of the key characteristics of
kink-antikink collisions, such as the critical velocity and the multi-bounce
windows, are sensitively dependent on the trap strength parameter, as well as
the initial displacement of the kink and antikink
From policy to practice: exploring practitioners' perspectives on social enterprise policy claims
The pitfalls and promise of liquid biopsies for diagnosing and treating solid tumors in children : a review
Cell-free DNA profiling using patient blood is emerging as a non-invasive complementary technique for cancer genomic characterization. Since these liquid biopsies will soon be integrated into clinical trial protocols for pediatric cancer treatment, clinicians should be informed about potential applications and advantages but also weaknesses and potential pitfalls. Small retrospective studies comparing genetic alterations detected in liquid biopsies with tumor biopsies for pediatric solid tumor types are encouraging. Molecular detection of tumor markers in cell-free DNA could be used for earlier therapy response monitoring and residual disease detection as well as enabling detection of pathognomonic and therapeutically relevant genomic alterations.
Conclusion: Existing analyses of liquid biopsies from children with solid tumors increasingly suggest a potential relevance for molecular diagnostics, prognostic assessment, and therapeutic decision-making. Gaps remain in the types of tumors studied and value of detection methods applied. Here we review the current stand of liquid biopsy studies for pediatric solid tumors with a dedicated focus on cell-free DNA analysis. There is legitimate hope that integrating fully validated liquid biopsy-based innovations into the standard of care will advance patient monitoring and personalized treatment of children battling solid cancers
Mapping species distributions: A comparison of skilled naturalist and lay citizen science recording
To assess the ability of traditional biological recording schemes and lay citizen science approaches to gather data on species distributions and changes therein, we examined bumblebee records from the UK’s national repository (National Biodiversity Network) and from BeeWatch. The two recording approaches revealed similar relative abundances of bumblebee species but different geographical distributions. For the widespread common carder (Bombus pascuorum), traditional recording scheme data were patchy, both spatially and temporally, reflecting active record centre rather than species distribution. Lay citizen science records displayed more extensive geographic coverage, reflecting human population density, thus offering better opportunities to account for recording effort. For the rapidly spreading tree bumblebee (Bombus hypnorum), both recording approaches revealed similar distributions due to a dedicated mapping project which overcame the patchy nature of naturalist records. We recommend, where possible, complementing skilled naturalist recording with lay citizen science programmes to obtain a nation-wide capability, and stress the need for timely uploading of data to the national repository
Insights into enterotoxigenic Escherichia coli diversity in Bangladesh utilizing genomic epidemiology
Effect of cyclosporine on hepatic cytosolic estrogen and androgen receptor levels before and after partial hepatectomy
Estrogen and androgen receptors within the liver have been reported to modulate the hepatic regenerative response to partial hepatectomy. Moreover, cyclosporine has several untoward effects that might occur as a consequence of alterations in sex hormone activity. To evaluate these questions the following experiments were performed. Estrogen and androgen receptors in cytosol were quantitated in livers of rats treated with cyclosporine or olive oil vehicle before and after partial hepatectomy or a sham operation. Ornithine decarboxylase activity and thymidine kinase activity were assessed as indices of hepatic regeneration. Preoperative levels of estrogen receptor activity in the hepatic cytosol were significantly greater in rats treated with cyclosporine as compared to vehicle treated controls (P<0.01). In contrast, preoperative levels of androgen receptor activity in the cyclosporine-treated and vehicle-treated animals were similar. Following partial hepatectomy, a reduction in the activity of both sex hormone receptors in the hepatic cytosol was observed and was compatible with results described previously in normal animals. Unexpectedly the preoperative levels of ornithine decarboxylase (P<0.01) and thymidine kinase activity (P<0.01) were significantly greater in the rats treated with cyclosporine as compared to the vehicle treated controls. As expected, ornithine decarboxylase activity (at 6 hr) and thymidine kinase activity (at 24 hr) rose and peaked in response to a partial hepatectomy but were significantly greater (P<0.05) in the rats treated with cyclosporine as compared to the vehicle. These results show that cyclosporine treatment causes an increase in the hepatic content of estrogen receptor activity that is associated with an enhanced potential for a regenerative response. These effects of cyclosporine treatment on the sex hormone receptor levels in liver may explain the mechanisms responsible for some of the untoward effects of treatment with this agent. © 1990 Plenum Publishing Corporation
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Ins and outs of the cultural polis: informality, culture and governance in the global South
This paper provides an epistemological critique of informality by focusing on cultural governance in two cities of the global South, Rio de Janeiro, Brazil, and Dakar, Senegal. Aiming to enrich debates about urban creativity and urban cultural policy, which are still mainly focused on and articulated from the global North, we consider the broad field of ‘informality’ research as an entry point for such a discussion. Using case studies from African and Latin American contexts, we focus on the interstices of cultural policy and the borderlands of (in)formality, examining how governmental institutions are entangled in informal processes, and how grassroots cultural interventions become part of mainstream cultural circuits. The analysis sheds light on how these creative spaces of cultural production, located in Southern contexts of urban extremes, contribute to the vitality of informal urbanisms and unsettle predominant views that see them merely as sites ofinfrastructural poverty and social exclusion. The paper suggests that a creative remapping of informality, through an inquiry of the ‘ins’ and ‘outs’ of the cultural polis, could improve our translating capacity of academic discourse into institutional/policy-related operations
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