Primary Teratoma of the Lesser Sac: Lesser Sac Teratoma

Germ cell tumors predominantly involve the gonads but may rarely be found outside of the gonads, primarily in midline structures. We describe the case of a 27-year-old male with an asymptomatic 8 cm teratoma located within the lesser sac of his omentum. This is the fourth case of a teratoma located within the lesser sac of the omentum, which provides the opportunity to make some comparisons. Finally, we discuss some of the etiologic theories behind extragonadal germ cell tumors and how they relate to teratomas in the lesser sac

Detection of non-melanoma skin cancer by in vivo fluorescence imaging with fluorocoxib A.

Non-melanoma skin cancer (NMSC) is the most common form of cancer in the US and its incidence is increasing. The current standard of care is visual inspection by physicians and/or dermatologists, followed by skin biopsy and pathologic confirmation. We have investigated the use of in vivo fluorescence imaging using fluorocoxib A as a molecular probe for early detection and assessment of skin tumors in mouse models of NMSC. Fluorocoxib A targets the cyclooxygenase-2 (COX-2) enzyme that is preferentially expressed by inflamed and tumor tissue, and therefore has potential to be an effective broadly active molecular biomarker for cancer detection. We tested the sensitivity of fluorocoxib A in a BCC allograft SCID hairless mouse model using a wide-field fluorescence imaging system. Subcutaneous allografts comprised of 1000 BCC cells were detectable above background. These BCC allograft mice were imaged over time and a linear correlation (R(2) = 0.8) between tumor volume and fluorocoxib A signal levels was observed. We also tested fluorocoxib A in a genetically engineered spontaneous BCC mouse model (Ptch1(+/-) K14-Cre-ER2 p53(fl/fl)), where sequential imaging of the same animals over time demonstrated that early, microscopic lesions (100 μm size) developed into visible macroscopic tumor masses over 11 to 17 days. Overall, for macroscopic tumors, the sensitivity was 88% and the specificity was 100%. For microscopic tumors, the sensitivity was 85% and specificity was 56%. These results demonstrate the potential of fluorocoxib A as an in vivo imaging agent for early detection, margin delineation and guided biopsies of NMSCs

ASCA Observation of an X-Ray-Luminous Active Nucleus in Markarian 231

We have obtained a moderately long (100 kilosecond) ASCA observation of the Seyfert 1 galaxy Markarian 231, the most luminous of the local ultraluminous infrared galaxy (ULIRG) population. In the best-fitting model we do not see the X-ray source directly; the spectrum consists of a scattered power-law component and a reflection component, both of which have been absorbed by a column N_H \approx 3 X 10^(22)/cm^2. About 3/4 of the observed hard X-rays arise from the scattered component, reducing the equivalent width of the iron K alpha line. The implied ratio of 1-10 keV X-ray luminosity to bolometric luminosity, L_x/L_bol \sim 2%, is typical of Sy 1 galaxies and radio-quiet QSOs of comparable bolometric luminosities, and indicates that the bolometric luminosity is dominated by the AGN. Our estimate of the X-ray luminosity also moves Mrk 231 in line with the correlations found for AGN with extremely strong Fe II emission. A second source separated by about 2 arcminutes is also clearly detected, and contributes about 25% of the total flux.Comment: 11 pages, 3 figures; to appear in ApJ Letter

Low angular-dispersion microwave absorption of a metal dual-period nondiffracting hexagonal grating

Copyright © 2005 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 86 (2005) and may be found at http://link.aip.org/link/?APPLAB/86/184103/1The microwave (11.3<λ0<16.7 mm) reflectivity response of a nondiffracting dual-period hexagonal grating is explored. In three directions at 60° to each other, the aluminum grating has a repeat period of 7.2 mm in which are three equally spaced grooves, one being slightly shallower than the other two. This dual-period (λg and λg/3) structure exhibits strong microwave absorption at several different frequencies. In addition, some of the absorptions are almost completely independent of the angle of incidence and polarization of the microwave radiation

Inhibition of MHC Class I Is a Virulence Factor in Herpes Simplex Virus Infection of Mice

Herpes simplex virus (HSV) has a number of genes devoted to immune evasion. One such gene, ICP47, binds to the transporter associated with antigen presentation (TAP) 1/2 thereby preventing transport of viral peptides into the endoplasmic reticulum, loading of peptides onto nascent major histocompatibility complex (MHC) class I molecules, and presentation of peptides to CD8 T cells. However, ICP47 binds poorly to murine TAP1/2 and so inhibits antigen presentation by MHC class I in mice much less efficiently than in humans, limiting the utility of murine models to address the importance of MHC class I inhibition in HSV immunopathogenesis. To address this limitation, we generated recombinant HSVs that efficiently inhibit antigen presentation by murine MHC class I. These recombinant viruses prevented cytotoxic T lymphocyte killing of infected cells in vitro, replicated to higher titers in the central nervous system, and induced paralysis more frequently than control HSV. This increase in virulence was due to inhibition of antigen presentation to CD8 T cells, since these differences were not evident in MHC class I-deficient mice or in mice in which CD8 T cells were depleted. Inhibition of MHC class I by the recombinant viruses did not impair the induction of the HSV-specific CD8 T-cell response, indicating that cross-presentation is the principal mechanism by which HSV-specific CD8 T cells are induced. This inhibition in turn facilitates greater viral entry, replication, and/or survival in the central nervous system, leading to an increased incidence of paralysis

The role of ondansetron in the management of cholestatic or uremic pruritis - a systematic review

Pruritus associated with hepatic or renal failure can be a troublesome symptom, refractory to treatment, associated with significant physical and emotional distress, and reduction in quality of life for patients already burdened with chronic disease. Serotonin has been implicated as a possible pathological mediator, and therefore 5HT3 antagonists have been suggested as a possible therapeutic intervention. Objectives This review of the literature systematically explores the role of ondansetron in the management of cholestatic or uraemic pruritus. Methods Electronic databases were systematically searched for randomized controlled trials (RCTs) examining the role of ondansetron in cholestatic or uraemic pruritus between 1966 and 2008. Results Five RCTs were included in this systematic review: three for cholestatic pruritus, and two for uraemic pruritus. All trials examined ondansetron versus placebo, however with differing treatment protocols. Overall, three studies showed no benefit to ondansetron over placebo, however two studies in cholestatic pruritus showed small reductions in pruritus with questionable clinical significance. Conclusion Ondansetron was demonstrated to have negligible effect on cholestatic or uraemic pruritus on the basis of a limited number of studies

A New Perspective on Cosmic Coincidence Problems

Cosmological data suggest that we live in an interesting period in the history of the universe when \rho_\Lambda \sim \rho_M \sim \rho_R. The occurence of any epoch with such a "triple coincidence" is puzzling, while the question of why we happen to live during this special epoch is the "Why now?" problem. We introduce a framework which makes the triple coincidence inevitable; furthermore, the ``Why now?'' problem is transformed and greatly ameliorated. The framework assumes that the only relevant mass scales are the electroweak scale, M_{EW}, and the Planck scale, M_{Pl}, and requires \rho_\Lambda^{1/4} \sim M_{EW}^2/M_{Pl} parametrically. Assuming that the true vacuum energy vanishes, we present a simple model where a false vacuum energy yields a cosmological constant of this form.Comment: 5 pages, 1 figure, uses psfig. Refs added, slightly enhance

Selective transmission through very deep zero-order metallic gratings at microwave frequencies

Copyright © 2000 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters 77 (2000) and may be found at http://link.aip.org/link/?APPLAB/77/2789/1Zero-order metal grating structures are found to give extraordinary selective transmission at microwave frequencies through the resonant excitation of coupled surface waves. The metal slat structures with dielectric spacings as small as 250 µm strongly transmit wavelengths of several millimeters. A simple interpretation of these novel results which treats the deep grating structures as "filled" Fabry–Perot cavity systems gives model transmissivities which agree very well with the experimental data