Genomic imprinting variations in the mouse type 3 deiodinase gene between tissues and brain regions.

The Dio3 gene, which encodes for the type 3 deiodinase (D3), controls thyroid hormone (TH) availability. The lack of D3 in mice results in tissue overexposure to TH and a broad neuroendocrine phenotype. Dio3 is an imprinted gene, preferentially expressed from the paternally inherited allele in the mouse fetus. However, heterozygous mice with paternal inheritance of the inactivating Dio3 mutation exhibit an attenuated phenotype when compared with that of Dio3 null mice. To investigate this milder phenotype, the allelic expression of Dio3 was evaluated in different mouse tissues. Preferential allelic expression of Dio3 from the paternal allele was observed in fetal tissues and neonatal brain regions, whereas the biallelic Dio3 expression occurred in the developing eye, testes, and cerebellum and in the postnatal brain neocortex, which expresses a larger Dio3 mRNA transcript. The newborn hypothalamus manifests the highest degree of Dio3 expression from the paternal allele, compared with other brain regions, and preferential allelic expression of Dio3 in the brain relaxed in late neonatal life. A methylation analysis of two regulatory regions of the Dio3 imprinted domain revealed modest but significant differences between tissues, but these did not consistently correlate with the observed patterns of Dio3 allelic expression. Deletion of the Dio3 gene and promoter did not result in significant changes in the tissue-specific patterns of Dio3 allelic expression. These results suggest the existence of unidentified epigenetic determinants of tissue-specific Dio3 imprinting. The resulting variation in the Dio3 allelic expression between tissues likely explains the phenotypic variation that results from paternal Dio3 haploinsufficiency.This is the final version of the article. It is available from the Endocrine Society in Molecular Endocrinology here: http://press.endocrine.org/doi/pdf/10.1210/me.2014-1210

Radiometric measurements of the microwave emissivity of foam

Includes bibliographical references.Radiometric measurements of the microwave emissivity of foam were conducted during May 2000 at the Naval Research Laboratory's Chesapeake Bay Detachment using radiometers operating at 10.8 and 36.5 GHz. Horizontal and vertical polarization measurements were performed at 36.5 GHz; horizontal, vertical, +45°, ­45°, left-circular, and right-circular polarization measurements were obtained at 10.8 GHz. These measurements were carried out over a range of incidence angles from 30° to 60°. Surface foam was generated by blowing compressed air through a matrix of gas-permeable tubing supported by an aluminum frame and floats. Video micrographs of the foam were used to measure bubble size distribution and foam layer thickness. A video camera was boresighted with the radiometers to determine the beam-fill fraction of the foam generator. Results show emissivities that were greater than 0.9 and approximately constant in value over the range of incidence angles for vertically polarized radiation at both 10.8 and 36.5 GHz, while emissivities of horizontally polarized radiation showed a gradual decrease in value as incidence angle increased. Emissivities at +45°, ­45°, left-circular, and right-circular polarizations were all very nearly equal to each other and were in turn approximately equal to the average values of the horizontal and vertical emissivities in each case.This work was sponsored by the Department of the Navy, Office of Naval Research under Award N0014-00-1-280 to the University of Massachusetts, Award N00014-00-0152 to the University of Washington, and Award N0001400WX21032 to the Naval Research Laboratory

Evaluating the effectiveness of a radiation safety training intervention for oncology nurses: a pretest – intervention – posttest study

BACKGROUND: Radiation, for either diagnosis or treatment, is used extensively in the field of oncology. An understanding of oncology radiation safety principles and how to apply them in practice is critical for nursing practice. Misconceptions about radiation are common, resulting in undue fears and concerns that may negatively impact patient care. Effectively educating nurses to help overcome these misconceptions is a challenge. Historically, radiation safety training programs for oncology nurses have been compliance-based and behavioral in philosophy. METHODS: A new radiation safety training initiative was developed for Memorial Sloan-Kettering Cancer Center (MSKCC) adapting elements of current adult education theories to address common misconceptions and to enhance knowledge. A research design for evaluating the revised training program was also developed to assess whether the revised training program resulted in a measurable and/or statistically significant change in the knowledge or attitudes of nurses toward working with radiation. An evaluation research design based on a conceptual framework for measuring knowledge and attitude was developed and implemented using a pretest-intervention-posttest approach for 15% of the study population of 750 inpatient registered oncology nurses. RESULTS: As a result of the intervention program, there was a significant difference in nurse's cognitive knowledge as measured with the test instrument from pretest (58.9%) to posttest (71.6%). The evaluation also demonstrated that while positive nursing attitudes increased, the increase was significant for only 5 out of 9 of the areas evaluated. CONCLUSION: The training intervention was effective for increasing cognitive knowledge, but was less effective at improving overall attitudes. This evaluation provided insights into the effectiveness of training interventions on the radiation safety knowledge and attitude of oncology nurses

Flight Development for Cryogenic Fluid Management in Support of Exploration Missions

This paper describes the results of the "Experimentation for the Maturation of Deep Space Cryogenic Refueling Technology" study. The purposes of this study were to identify cryogenic fluids management technologies requiring low gravity flight experiments to bring to technology readiness level (TRL) 5-6; to study many possible flight experiment options; and to develop near-term low-cost flight experiment concepts to mature core technologies of refueling. A total of twenty-five white papers were prepared in the course of this study. Each white paper is briefly summarized and relevant references cited. A total of 90 references are cited

Effective Rheology of Bubbles Moving in a Capillary Tube

We calculate the average volumetric flux versus pressure drop of bubbles moving in a single capillary tube with varying diameter, finding a square-root relation from mapping the flow equations onto that of a driven overdamped pendulum. The calculation is based on a derivation of the equation of motion of a bubble train from considering the capillary forces and the entropy production associated with the viscous flow. We also calculate the configurational probability of the positions of the bubbles.Comment: 4 pages, 1 figur

Lipoglycans Contribute to Innate Immune Detection of Mycobacteria

Innate immune recognition is based on the detection, by pattern recognition receptors (PRRs), of molecular structures that are unique to microorganisms. Lipoglycans are macromolecules specific to the cell envelope of mycobacteria and related genera. They have been described to be ligands, as purified molecules, of several PRRs, including the C-type lectins Mannose Receptor and DC-SIGN, as well as TLR2. However, whether they are really sensed by these receptors in the context of a bacterium infection remains unclear. To address this question, we used the model organism Mycobacterium smegmatis to generate mutants altered for the production of lipoglycans. Since their biosynthesis cannot be fully abrogated, we manipulated the biosynthesis pathway of GDP-Mannose to obtain some strains with either augmented (∼1.7 fold) or reduced (∼2 fold) production of lipoglycans. Interestingly, infection experiments demonstrated a direct correlation between the amount of lipoglycans in the bacterial cell envelope on one hand and the magnitude of innate immune signaling in TLR2 reporter cells, monocyte/macrophage THP-1 cell line and human dendritic cells, as revealed by NF-κB activation and IL-8 production, on the other hand. These data establish that lipoglycans are bona fide Microbe-Associated Molecular Patterns contributing to innate immune detection of mycobacteria, via TLR2 among other PRRs

Involvement of Cox-2 in the metastatic potential of chemotherapy-resistant breast cancer cells

<p>Abstract</p> <p>Background</p> <p>A major problem with the use of current chemotherapy regimens for several cancers, including breast cancer, is development of intrinsic or acquired drug resistance, which results in disease recurrence and metastasis. However, the mechanisms underlying this drug resistance are unknown. To study the molecular mechanisms underlying the invasive and metastatic activities of drug-resistant cancer cells, we generated a doxorubicin-resistant MCF-7 breast cancer cell line (MCF-7/DOX).</p> <p>Methods</p> <p>We used MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays, flow cytometry assays, DNA fragmentation assays, Western blot analysis, cell invasion assays, small interfering RNA (siRNA) transfection, reverse transcription-polymerase chain reaction, experimental lung metastasis models, and gelatin and fibrinogen/plasminogen zymography to study the molecular mechanism of metastatic activities in MCF-7/DOX cells.</p> <p>Results</p> <p>We found that MCF-7/DOX acquired invasive activities. In addition, Western blot analysis showed increased expression of epidermal growth factor receptor (EGFR) and Cox-2 in MCF-7/DOX cells. Inhibition of Cox-2, phosphoinositide 3-kinase (PI3K)/Akt, or mitogen-activated protein kinase (MAPK) pathways effectively inhibited the invasive activities of MCF-7/DOX cells. Gelatin and fibrinogen/plasminogen zymography analysis showed that the enzymatic activities of matrix metalloproteinase-2 (MMP-2), MMP-9, and urokinase-type plasminogen activator were markedly higher in MCF-7/DOX cells than in the MCF-7 cells. <it>In vitro </it>invasion assays and mouse models of lung metastasis demonstrated that MCF-7/DOX cells acquired invasive abilities. Using siRNAs and agonists specific for prostaglandin E (EP) receptors, we found that EP1 and EP3 played important roles in the invasiveness of MCF-7/DOX cells.</p> <p>Conclusions</p> <p>We found that the invasive activity of MCF-7/DOX cells is mediated by Cox-2, which is induced by the EGFR-activated PI3K/Akt and MAPK pathways. In addition, EP1 and EP3 are important in the Cox-2-induced invasion of MCF-7/DOX cells. Therefore, not only Cox-2 but also EP1 and EP3 could be important targets for chemosensitization and inhibition of metastasis in breast cancers that are resistant to chemotherapy.</p