279 research outputs found

    An inducible CiliaGFP mouse model for in vivo visualization and analysis of cilia in live tissue

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    BACKGROUND: Cilia are found on nearly every cell type in the mammalian body, and have been historically classified as either motile or immotile. Motile cilia are important for fluid and cellular movement; however, the roles of non-motile or primary cilia in most tissues remain unknown. Several genetic syndromes, called the ciliopathies, are associated with defects in cilia structure or function and have a wide range of clinical presentations. Much of what we know about the formation and maintenance of cilia comes from model systems like C. elegans and Chalmydomonas. Studies of mammalian cilia in live tissues have been hampered by difficulty visualizing them. RESULTS: To facilitate analyses of mammalian cilia function we generated an inducible Cilia(GFP) mouse by targeting mouse cDNA encoding a cilia-localized protein somatostatin receptor 3 fused to GFP (Sstr3::GFP) into the ROSA26 locus. In this system, Sstr3::GFP is expressed from the ubiquitous ROSA26 promoter after Cre mediated deletion of an upstream Neo cassette flanked by lox P sites. Fluorescent cilia labeling was observed in a variety of live tissues and after fixation. Both cell-type specific and temporally regulated cilia labeling were obtained using multiple Cre lines. The analysis of renal cilia in anesthetized live mice demonstrates that cilia commonly lay nearly parallel to the apical surface of the tubule. In contrast, in more deeply anesthetized mice the cilia display a synchronized, repetitive oscillation that ceases upon death, suggesting a relationship to heart beat, blood pressure or glomerular filtration. CONCLUSIONS: The ability to visualize cilia in live samples within the Cilia(GFP) mouse will greatly aid studies of ciliary function. This mouse will be useful for in vivo genetic and pharmacological screens to assess pathways regulating cilia motility, signaling, assembly, trafficking, resorption and length control and to study cilia regulated physiology in relation to ciliopathy phenotypes

    Developing Creativity: Artificial Barriers in Artificial Intelligence

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    The greatest rhetorical challenge to developers of creative artificial intelligence systems is convincingly arguing that their software is more than just an extension of their own creativity. This paper suggests that “creative autonomy,” which exists when a system not only evaluates creations on its own, but also changes its standards without explicit direction, is a necessary condition for making this argument. Rather than requiring that the system be hermetically sealed to avoid perceptions of human influence, developing creative autonomy is argued to be more plausible if the system is intimately embedded in a broader society of other creators and critics. Ideas are presented for constructing systems that might be able to achieve creative autonomy

    Role of Integrin Expression in Adenovirus-Mediated Gene Delivery to the Intestinal Epithelium

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    Overview summary Previous studies of adenovirus-mediated gene transfer of the interleukin-1 receptor antagonist protein to rat jejunum have produced limited gene expression. In the present study, we have shown that integrins play a significant role in efficient adenoviral infection of the intestinal epithelium. As enterocytes differentiate, integrin expression decreases. This coincides with significant reduction in adenoviral transduction efficiency. Results from two in vitro models of the intestinal epithelium (Caco-2 and IEC-18 cells) show that αvβ3 integrins have the most influence on adenoviral internalization. Results from screening of rat intestinal segments for expression of the αvβ5 integrin suggest that, based on integrin expression, the ileum is a prime target for efficient adenovirus-mediated gene transfer. We have also found that administration of immunomodulating agents and inflammatory disease states provide a favorable environment for efficient internalization of adenoviral vectors due to up-regulation of integrin receptors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63160/1/hum.1998.9.4-561.pd

    Bad bosses and self-verification: the moderating role of core self-evaluations with trust in workplace management

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    Who responds most strongly to supervisor social undermining? Building on self-verification theory (Swann, 1983, 1987), we theorize that employees with positive views of the self (i.e., higher core self-evaluations [CSEs]) who also maintain higher trust in workplace management are more likely to experience heightened stress and turnover intentions when undermined. We argue that this subset of employees (high CSE, high trust) are more likely to feel misunderstood when undermined by their supervisor and that this lack of self-verification partially explains their stronger responses to supervisor undermining. We find initial support for the first part of our model in a study of 259 healthcare workers in the United States and replicate and extend our findings in the second study of 330 employees in the United Kingdom. Our results suggest that the employees Human Resources often wishes to attract and retain—employees with high CSE and high trust in workplace management—react most strongly to supervisor social undermining

    The Invisible Disease: Making Sense of an Osteoporosis Diagnosis in Older Age

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    Osteoporosis (low bone density) is a potentially serious disease which mainly affects women older than 50 years. National screening programs for osteoporosis are being developed in the United Kingdom. It is important to assess the psychological experience of receiving a positive diagnosis from a population-based screening program so that psychological distress does not outweigh medical benefits. Little research has been conducted in this field. In our study, we explored the experience of being diagnosed with osteoporosis following screening. We interviewed 10 women aged 68 to 79 who were recruited from a population-based osteoporosis screening trial. Four themes emerged from our interpretative phenomenological analysis of the interviews: osteoporosis is a routine medical condition, lack of physical evidence creates doubt, the mediating role of medical care, and protecting the self from distress. Our findings emphasize the complexity attached to receiving a positive screening result. We suggest considerations for health care providers

    Drug–virus interaction: effect of administration of recombinant adenoviruses on the pharmacokinetics of docetaxel in a rat model

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    Modern cancer therapy combines recombinant viruses with traditional chemotherapeutic agents that are metabolized by hepatic cytochrome P450 3A4 (CYP3A4). A single dose of recombinant adenovirus (Ad) expressing beta-galactosidase (AdlacZ) significantly alters CYP3A2, the correlate of CYP3A4, in rats for 14 days. Recombinant adenovirus expressing human p53 (Adp53) also suppresses CYP3A2. Plasma clearance of docetaxel (DTX) in animals given AdlacZ (3.38 ± 0.22 L/h/kg) was significantly lower than that of those given DTX alone (6.41 ± 1.10 L/h/kg, p≤0.05). Area under the plasma concentration-time curve of DTX in rats given AdlacZ (2,987.37 ± 197.97 ng/ml/h) was significantly greater than those given drug alone (1,666.59 ± 317.04 ng/ml/h, p≤0.05). Both viruses prolonged DTX half-life (t1/2). Ad infection may cause significant variability in the pharmacokinetics and pharmacodynamics of anti-cancer agents and should be considered when designing therapeutic regimens for patients with viral infection and those enrolled in clinical trials employing recombinant viruses

    Chitosan Modification of Adenovirus to Modify Transfection Efficiency in Bovine Corneal Epithelial Cells

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    BACKGROUND: The purpose of this study is to modulate the transfection efficiency of adenovirus (Ad) on the cornea by the covalent attachment of chitosan on adenoviral capsids via a thioether linkage between chitosan modified with 2-iminothiolane and Ad cross-linked with N-[gamma-maleimidobutyryloxy]succinimide ester (GMBS). METHODOLOGY/PRINCIPAL FINDINGS: Modified Ad was obtained by reaction with the heterobifunctional crosslinking reagent, GMBS, producing maleimide-modified Ad (Ad-GMBS). Then, the chitosan-SH was conjugated to Ad-GMBS via a thioether bond at different ratios of Ad to GMBS to chitosan-SH. The sizes and zeta potentials of unmodified Ad and chitosan-modified Ads were measured, and the morphologies of the virus particles were observed under transmission electron microscope. Primary cultures of bovine corneal epithelial cells were transfected with Ads and chitosan-modified Ads in the absence or presence of anti-adenovirus antibodies. Chitosan modification did not significantly change the particle size of Ad, but the surface charge of Ad increased significantly from -24.3 mV to nearly neutral. Furthermore, primary cultures of bovine corneal epithelial cells were transfected with Ad or chitosan-modified Ad in the absence or presence of anti-Ad antibodies. The transfection efficiency was attenuated gradually with increasing amounts of GMBS. However, incorporation of chitosan partly restored transfection activity and rendered the modified antibody resistant to antibody neutralization. CONCLUSIONS/SIGNIFICANCE: Chitosan can provide a platform for chemical modification of Ad, which offers potential for further in vivo applications

    Educating Cancer Prevention Researchers in Emerging Biobehavioral Models: Lessons Learned

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    To increase the adoption of transdisciplinary research methods among future cancer prevention investigators, faculty members from The University of Texas MD Anderson Cancer Center developed a graduate-level course in biobehavioral methods in cancer prevention research. Two instructors paired by topic and area of expertise offered an hour-long lecture-based seminar every week for 15 weeks during the spring semester of 2010. Students and presenters both evaluated the overall course content and delivery method, as well as each session. A total of 11 students and 22 presenters participated in the course. In each class session, one presenter was from a behavioral science background,and the other was from a biological sciences background. Both presenters and students expressed overall satisfaction with the content and format of the course. The presentation of topics from a transdisciplinary perspective and interaction with presenters from both biological and behavioral sciences are valuable and can help junior researchers prepare to meet the emerging challenges in cancer prevention research

    Randomised trial of a decision aid and its timing for women being tested for a BRCA1/2 mutation

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    Contains fulltext : 57882.pdf (publisher's version ) (Closed access)The aim of the study was to evaluate the impact of a decision aid (DA) and its timing in women being tested for a BRCA1/2 mutation. Women with and without a previous history of cancer were included after blood sampling for genetic testing. The DA consisted of a brochure and video providing information on screening and prophylactic surgery. To evaluate the impact of the DA, women were randomised to the DA group (n=184), receiving the DA 2 weeks after blood sampling, or to the control group (n=184). To evaluate the impact of timing, mutation carriers who had received the DA before the test result (n=47) were compared to mutation carriers who received the DA after the test result (n=42). Data were collected on well-being, treatment choice, decision and information related outcomes. The impact of the DA was measured 4 weeks after blood sampling. The impact of timing was measured 2 weeks after a positive test result. The DA had no impact on well-being. Regarding decision related outcomes, the DA group more frequently considered prophylactic surgery (P=0.02) corroborated with higher valuations (P=0.04). No differences were found for the other decision related outcomes. Regarding information related outcomes, the DA group felt better informed (P=0.00), was more satisfied with the information (P=0.00), and showed more accurate risk perceptions. Timing of the DA had no effect on any of the outcomes. No interactions were found between the DA and history of cancer. In conclusion, women being tested for a BRCA1/2 mutation benefit from the DA on information related outcomes. Because timing had no effect, the DA is considered useful either before or after the test result
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