958 research outputs found

    Solitary colon metastasis from renal cell carcinoma nine years after nephrectomy: A case report

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    AbstractIntroductionRenal cell carcinoma (RCC) is the most common renal malignancy in adults. Metastatic disease is relatively common at presentation and frequently involves the lung, bone, brain, liver and adrenal glands. After curative resection, there is a 30–40% risk of recurrence, and a 10% risk of developing metastatic disease after 5 years. The gastrointestinal tract, particularly the colon, represents a very uncommon site of late metastatic disease.Presentation of CaseWe present a case of a 67 year-old-male who underwent a left radical nephrectomy for RCC 9 years before presenting with a metastatic large bowel obstruction. He was later found to have a near-completely obstructing mass in the rectosigmoid colon and underwent a sigmoidectomy with anterior resection of the upper rectum. Histopathology confirmed metastatic RCC confined to the colonic wall with negative microscopic margins.DiscussionThe tendency of RCC to metastasize to unusual sites such as the pancreas or thyroid gland has been widely reported. However, cases of colon metastasis from RCC are extremely rare. Despite the absence of randomized prospective data, widespread consensus supports the surgical treatment of solitary and oligometastatic disease in light of the poor patient outcomes in non-surgically treated disease (Milovic et al., 2013) [3]. Multiple groups have reported favorable outcomes for surgically resected solitary metastatic disease with long disease-free intervals and good performance status.ConclusionThe colon is a potential, though uncommon, site for solitary metastasis from RCC. The clinical presentation is frequently several years after initial curative resection. Oncologic resection with negative margins may result in long-term survival in patients with isolated metastatic disease

    Pulsar Constraints on Neutron Star Structure and Equation of State

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    With the aim of constraining the structural properties of neutron stars and the equation of state of dense matter, we study sudden spin-ups, glitches, occurring in the Vela pulsar and in six other pulsars. We present evidence that glitches represent a self-regulating instability for which the star prepares over a waiting time. The angular momentum requirements of glitches in Vela indicate that at least 1.4% of the star's moment of inertia drives these events. If glitches originate in the liquid of the inner crust, Vela's `radiation radius' must exceed ~12 km for a mass of 1.4 solar masses. Observational tests of whether other neutron stars obey this constraint will be possible in the near future.Comment: 5 pages, including figures. To appear in Physical Review Letter

    JC Virus Mediates Invasion and Migration in Colorectal Metastasis

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    INTRODUCTION:JC Virus (JCV), a human polyomavirus, is frequently present in colorectal cancers (CRCs). JCV large T-Ag (T-Ag) expressed in approximately half of all CRC's, however, its functional role in CRC is poorly understood. We hypothesized that JCV T-Ag may mediate metastasis in CRC cells through increased migration and invasion. MATERIAL AND METHODS:CRC cell lines (HCT116 and SW837) were stably transfected with JCV early transcript sequences cloned into pCR3 or empty vectors. Migration and invasion assays were performed using Boyden chambers. Global gene expression analysis was performed to identify genetic targets and pathways altered by T-Ag expression. Microarray results were validated by qRT-PCR, protein expression analyses and immunohistochemistry. Matching primary CRCs and liver metastases from 33 patients were analyzed for T-Ag expression by immunohistochemistry. RESULTS:T-Ag expressing cell lines showed 2 to 3-fold increase in migration and invasion compared to controls. JCV T-Ag expression resulted in differential expression of several genetic targets, including genes that mediate cell migration and invasion. Pathway analysis suggested a significant involvement of these genes with AKT and MAPK signaling. Treatment with selective PI3K/AKT and MAPK pathway inhibitors resulted in reduced migration and invasion. In support of our in-vitro results, immunohistochemical staining of the advanced stage tumors revealed frequent JCV T-Ag expression in metastatic primary tumors (92%) as well as in their matching liver metastasis (73%). CONCLUSION:These data suggest that JCV T-Ag expression in CRC associates with a metastatic phenotype, which may partly be mediated through the AKT/MAPK signaling pathway. Frequent expression of JCV T-Ag in CRC liver metastasis provides further clues supporting a mechanistic role for JCV as a possible mediator of cellular motility and invasion in CRC

    Exploring Halo Substructure with Giant Stars IV: The Extended Structure of the Ursa Minor Dwarf Spheroidal

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    We present a large area photometric survey of the Ursa Minor dSph. We identify UMi giant star candidates extending to ~3 deg from the center of the dSph. Comparison to previous catalogues of stars within the tidal radius of UMi suggests that our photometric luminosity classification is 100% accurate. Over a large fraction of the survey area, blue horizontal branch stars associated with UMi can also be identified. The spatial distribution of both the UMi giant stars and the BHB stars are remarkably similar, and a large fraction of both samples of stars are found outside the tidal radius of UMi. An isodensity contour map of the stars within the tidal radius of UMi reveals two morphological peculiarities: (1) The highest density of dSph stars is offset from the center of symmetry of the outer isodensity contours. (2) The overall shape of the outer contours appear S-shaped. We find that previously determined King profiles with ~50' tidal radii do not fit well the distribution of our UMi stars. A King profile with a larger tidal radius produces a reasonable fit, however a power law with index -3 provides a better fit for radii > 20'. The existence of UMi stars at large distances from the core of the galaxy, the peculiar morphology of the dSph within its tidal radius, and the shape of its surface density profile all suggest that UMi is evolving significantly due to the tidal influence of the Milky Way. However, the photometric data on UMi stars alone does not allow us to determine if the candidate extratidal stars are now unbound or if they remain bound to the dSph within an extended dark matter halo. (Abridged)Comment: accepted by AJ, 32 pages, 15 figures, emulateapj5 styl

    Exploring Halo Substructure with Giant Stars. VI. Extended Distributions of Giant Stars Around the Carina Dwarf Spheroidal Galaxy -- How Reliable Are They?

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    The question of the existence of active tidal disruption around various dSph galaxies remains controversial. That debate often centers on the nature (bound vs. unbound) of extended populations of stars. However, the more fundamental issue of the very existence of the extended populations is still contentious. We present an evaluation of the debate centering on one particular dSph, Carina, for which claims both for and against the existence of stars beyond the King radius have been made. Our review includes an examination of all previous studies bearing on the Carina radial profile and shows that the survey method which achieves the highest detected dSph signal-to-background in the outer parts of the galaxy is the Washington M, T2 + DDO51 (MTD) filter approach from Paper II in this series. We then address statistical methods used to evaluate the reliability of MTD surveys in the presence of photometric errors and for which a new, a posteriori statistical analysis methodology is provided. Finally, these statistical methods are tested by new spectroscopy of stars in the MTD-selected Carina candidate sample. Of 74 candidate giants with follow-up spectroscopy, the MTD technique identified 61 new Carina members, including 8 stars outside the King radius. From a sample of 29 stars not initially identified as candidate Carina giants but that lie just outside of our selection criteria, 12 have radial velocities consistent with membership, including 5 extratidal stars. Carina is shown to have an extended population of giant stars extending to a major axis radius of 40' (1.44x the nominal King radius).Comment: 56 pages, 10 figures. Submitted to the Astronomical Journal, 2004 Sep 2

    Association of Exposure to Police Violence With Prevalence of Mental HealthSymptoms Among Urban Residents in the United States

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    Importance Police violence is reportedly widespread in the United States and may pose a significant risk to public mental health. Objective To examine the association between 12-month exposure to police violence and concurrent mental health symptoms independent of trauma history, crime involvement, and other forms of interpersonal violence exposure. Design, Setting, and Participants This cross-sectional, general population survey study of 1221 eligible adults was conducted in Baltimore, Maryland, and New York City, New York, from October through December 2017. Participants were identified through Qualtrics panels, an internet-based survey administration service using quota sampling. Exposures Past 12-month exposure to police violence, assessed using the Police Practices Inventory. Subtypes of violence exposure were coded according to the World Health Organization domains of violence (ie, physical, sexual, psychological, and neglectful). Main Outcomes and Measures Current Kessler Screening Scale for Psychological Distress (K6) score, past 12-month psychotic experiences (World Health Organization Composite International Diagnostic Interview), and past 12-month suicidal ideation and attempts. Results Of 1221 eligible participants, there were 1000 respondents (81.9% participation rate). The sample matched the adult population of included cities on race/ethnicity (non-Hispanic white, 339 [33.9%]; non-Hispanic black/African American, 390 [39.0%]; Hispanic/Latino, 178 [17.8%]; other, 93 [9.3%]), age (mean [SD], 39.8 [15.2] years), and gender (women, 600 [60.0%]; men, 394 [39.4%]; transgender, 6 [0.6%]) within 10% above or beyond 2010 census distributions. Twelve-month prevalence of police violence was 3.2% for sexual violence, 7.5% for physical violence without a weapon, 4.6% for physical violence with a weapon, 13.2% for psychological violence, and 14.9% for neglect. Police violence exposures were higher among men, people of color, and those identified as homosexual or transgender. Respondents reported suicidal ideation (9.1%), suicide attempts (3.1%), and psychotic experiences (20.6%). The mean (SD) K6 score was 5.8 (6.1). All mental health outcomes were associated with police violence exposure in adjusted logistic regression analyses. Physical violence with a weapon and sexual violence were associated with greater odds of psychotic experiences (odds ratio [95% CI]: 4.34 [2.05-9.18] for physical violence with a weapon; 6.61 [2.52-17.36] for sexual violence), suicide attempts (odds ratio [95% CI]: 7.30 [2.94-18.14] for physical violence with a weapon; 6.63 [2.64-16.64] for sexual violence), and suicidal ideation (odds ratio [95% CI]: 2.72 [1.30-5.68] for physical violence with a weapon; 3.76 [1.72-8.20] for sexual violence). Conclusions and Relevance Police violence was commonly reported, especially among racial/ethnic and sexual minorities. Associations between violence and mental health outcomes did not appear to be explained by confounding factors and appeared to be especially pronounced for assaultive forms of violence

    Keck spectroscopic survey of strongly lensed galaxies in Abell 1703: further evidence for a relaxed, unimodal cluster

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    Strong gravitational lensing is a unique tool to model with great accuracy the inner mass distribution of massive galaxy clusters. In particular, clusters with large Einstein radii provide a wealth of multiply imaged systems in the cluster core allowing to determine precisely the shape of the central dark matter profile. This paper presents a spectroscopic survey in the massive cluster Abell 1703, displaying a large Einstein radius (28" at z=2.8) and a high number of strongly-lensed systems including a central ring-like configuration. We used LRIS on Keck to target multiple images and lensed galaxy candidates, and use the measured redshifts to constrain the mass distribution of the cluster using a parametric model. The data enable us to measure accurate redshifts in good agreement with their photometric redshifts, and to update the identification of multiply imaged systems by discovering 3 new systems and a radial counter image. We also report the discovery of a remarkably bright ~3.6 L* i-band dropout at z=5.827 in our mask which is only moderately magnified by the cluster (~3.0+/-0.08). The improved parametric mass model, including 16 multiple systems with 10 spectroscopic redshifts, further constrains the cluster-scale mass distribution with a generalized NFW profile of best-fit logarithmic slope alpha=0.92+/-0.04, concentration c200=4.72+/-0.40 and scale radius rs=476+/-45 kpc. Our strong-lensing model predicts a large scale shear signal consistent with Subaru weak-lensing measurements out to 4 Mpc h^-1. Together with the fact that the strong-lensing modeling requires a single dark matter clump, this suggests that Abell 1703 is a relaxed, unimodal cluster. This unique cluster could be probed further using deep X-ray, SZ and dynamics analysis, for a detailed study of the physics in a relaxed cluster. (abridged)Comment: 11 pages, 6 figures, accepted for publication in A&A. Replaced with accepted versio
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