Reversed Expression of the JAK/STAT Pathway Related Proteins Prolactin Receptor and STAT5a in Normal and Abnormal Breast Epithelial Cells

The JAK/STAT pathway is important for cellular metabolism. One component, STAT5a, is activated in the breast upon prolactin to prolactin receptor (PRLR) binding facilitating the transcription of genes involved in lobule development. STAT5a was previously found to be expressed in most normal breast epithelial cells but not in many in situ or invasive carcinomas except secretory carcinomas which retain STAT5a expression. This report examines the JAK/STAT pathway in the breast through the detection of PRLR and STAT5a. Fifty breast tissues, including benign secretory change, microglandular adenosis, usual and atypical hyperplasia and in situ and invasive ductal carcinoma both usual and secretory, were obtained from the files of the Armed Forces Institute of Pathology. Sections were immunostained with antibodies to PRLR and STAT5a. PRLR was minimally detected on the surface of a few normal breast epithelial cells whereas STAT5a was greatly expressed in over 80% of normal cell nuclei. PRLR was also minimally detected in secretory carcinomas expressing STAT5a. However, the opposite pattern was seen in breast carcinomas lacking STAT5a expression. PRLR was abundantly expressed in these cells. This reversed expression may indicate a JAK/STAT pathway disturbance that could play a role in the initiation or maintenance of an abnormal breast phenotype

Noninvasive Measurement of Aminolevulinic Acid-Induced Protoporphyrin IX Fluorescence Allowing Detection of Murine Glioma In Vivo

Aminolevulinic acid (ALA)-induced protoporphyrin IX (PpIX) fluorescence is studied as a contrast agent for noninvasive detection of murine glioma, using the fluorescence-to-transmission ratio measured through the cranium. Signals measured prior to administration of ALA are very similar between control animals, 9L-GFP, and U251 tumor-bearing animals. However, 2 h after ALA administration, the PpIX signal from both tumor-bearing groups is significantly higher than the control group (9L-GFP group p-value=0.016, and U251 group p-value=0.004, relative to the control group). The variance in signal from the 9L-GFP group is much larger than either the control group or the U251 group, which is consistent with higher intrinsic PpIX fluorescence heterogeneity as seen in situ at ex vivo analysis. Decreasing the skin PpIX fluorescence via intentional photobleaching using red light (635 nm) is examined as a tool for increasing PpIX contrast between the tumor-bearing and control groups. The red light bleaching is found to increase the ability to accurately quantify PpIX fluorescence in vivo, but decreases the specificity of detection between tumor-bearing and nontumor-bearing groups

Cell clusters overlying focally disrupted mammary myoepithelial cell layers and adjacent cells within the same duct display different immunohistochemical and genetic features: implications for tumor progression and invasion

INTRODUCTION: Our previous studies detected focal disruptions in myoepithelial cell layers of several ducts with carcinoma in situ. The cell cluster overlying each of the myoepithelial disruptions showed a marked reduction in or a total loss of immunoreactivity for the estrogen receptor (ER). This is in contrast to the adjacent cells within the same duct, which were strongly immunoreactive for the ER. The current study attempts to confirm and expand previous observations on a larger scale. METHODS: Paraffin sections from 220 patients with ER-positive intraductal breast tumors were double immunostained with the same protocol previously used. Cross-sections of ducts lined by ≥ 40 epithelial cells were examined for myoepithelial cell layer disruptions and for ER expression. In five selected cases, ER-negative cells overlying the disrupted myoepithelial cell layer and adjacent ER-positive cells within the same duct were separately microdissected and assessed for loss of heterozygosity and microsatellite instability. RESULTS: Of the 220 cases with 5698 duct cross-sections examined, 94 showed disrupted myoepithelial cell layers with 405 focal disruptions. Of the 94 cases, 79 (84%) contained only ER-negative cell clusters, nine (9.6%) contained both ER-negative and ER-positive cell clusters, and six (6.4%) contained only ER-positive cell clusters overlying disrupted myoepithelial cell layers. Of the 405 disruptions, 350 (86.4%) were overlain by ER-negative cell clusters and 55 (13.6%) were overlain by ER-positive cell clusters (P < 0.01). Microdissected ER-negative and ER-positive cells within the same duct from all five selected cases displayed a different frequency or pattern of loss of heterozygosity and/or microsatellite instability at 10 of the 15 DNA markers. CONCLUSIONS: Cells overlying focally disrupted myoepithelial layers and their adjacent counterparts within the same duct displayed different immunohistochemical and molecular features. These features potentially represent an early sign of the formation of a biologically more aggressive cell clone and the myoepithelial cell layer breakdown possibly associated with tumor progression or invasion

Protoporphyrin IX Fluorescence Contrast in Invasive Glioblastomas is Linearly Correlated with Gd Enhanced Magnetic Resonance Image Contrast but has Higher Diagnostic Accuracy

The sensitivity and specificity of in vivo magnetic resonance (MR) imaging is compared with production of protoporphyrin IX (PpIX), determined ex vivo, in a diffusely infiltrating glioma. A human glioma transfected with green fluorescent protein, displaying diffuse, infiltrative growth, was implanted intracranially in athymic nude mice. Image contrast from corresponding regions of interest (ROIs) in in vivo MR and ex vivo fluorescence images was quantified. It was found that all tumor groups had statistically significant PpIX fluorescence contrast and that PpIX contrast demonstrated the best predictive power for tumor presence. Contrast from gadolinium enhanced T1-weighted (T1W+Gd) and absolute T2 images positively predicted the presence of a tumor, confirmed by the GFP positive (GFP+) and hematoxylin and eosin positive (H&E+) ROIs. However, only the absolute T2 images had predictive power from controls in ROIs that were GFP+ but H&E negative. Additionally, PpIX fluorescence and T1W+Gd image contrast were linearly correlated in both the GFP+ (r = 0.79, p\u3c1×10−8) and H&E+ (r = 0.74, p\u3c0.003) ROIs. The trace diffusion images did not have predictive power or significance from controls. This study indicates that gadolinium contrast enhanced MR images can predict the presence of diffuse tumors, but PpIX fluorescence is a better predictor regardless of tumor vascularity

Imaging of Glioma Tumor with Endogenous Fluorescence Tomography

Tomographic imaging of a glioma tumor with endogenous fluorescence is demonstrated using a noncontact single-photon counting fan-beam acquisition system interfaced with microCT imaging. The fluorescence from protoporphyrin IX (PpIX) was found to be detectable, and allowed imaging of the tumor from within the cranium, even though the tumor presence was not visible in the microCT image. The combination of single-photon counting detection and normalized fluorescence to transmission detection at each channel allowed robust imaging of the signal. This demonstrated use of endogenous fluorescence stimulation from aminolevulinic acid (ALA) and provides the first in vivo demonstration of deep tissue tomographic imaging with protoporphyrin IX. Fluorescence tomography provides a tool for preclinical molecular contrast agent assessment in oncology.1, 2, 3, 4 Systems have advanced in complexity to where noncontact imaging,5 automated boundary recovery,6 and sophisticated internal tissue shapes can be included in the recovered images. The translation of this work to humans will require molecular contrast agents that are amenable to regulatory approval and maintain tumor specificity in humans, where often nonspecific uptake of molecular imaging agents can decrease their utility. In this study, a new fluorescence tomography system coupled to microCT7 was used to illustrate diagnostic detection of orthotopic glioma tumors that were not apparent in the microCT images, using endogenous fluorescent contrast from protoporphyrin IX (PpIX). Glioma tumors provide significant endogenous fluorescence from PpIX,8, 9, 10, 11 and this is enhanced when the subject imaged has been administered aminolevulinic acid (ALA). The endogenous production process of PpIX is known to stem from the administered, ALA bypassing the regulatory inhibition of ALA synthase, allowing the heme synthesis pathway to proceed uninhibited. Since there is a limited supply of iron in the body, this process produces overabundance of PpIX rather than heme, and many tumors have been shown to have high yields of PpIX. Clinical trials with PpIX fluorescence guided resection of tumors have shown significant promise,12 and yet deep tissue imaging with PpIX fluorescence has not been exploited in clinical use. Early studies have shown that detection of these tumors with PpIX is feasible,13, 14 but no tomographic imaging has been used. This limitation in development has largely been caused by problems in wavelength filtering and low signal intensity, as well as background fluorescence from the skin limiting sensitivity to deeper structures. In the system developed and used here, this feasibility is demonstrated by imaging a human xenograft glioma model. To solve the sensitivity problem and study the ability to diagnostically image PpIX in vivo, time-correlated single-photon counting was used in the fluorescence tomography system, which provides maximum sensitivity. Figure 1a shows the system designed to match up with a microCT, allowing both x-ray structural and optical functional imaging sequentially. Lens-coupled detection of signals is acquired from the mouse using five time-resolved photomultiplier tubes (H7422P-50, Hamamatsu, Japan) with single-photon counting electronics (SPC-134 modules, Becker and Hickl GmbH, Germany). The system has fan-beam transmission geometry similar to a standard CT scanner, with single source delivery of a1-mW role= presentation \u3e1-mW pulsed diode laser light at 635nm role= presentation \u3e635nm , collimated to a 1-mm role= presentation \u3e1-mm effective area on the animal. The five detection lenses were arranged in an arc, each with 22.5-deg role= presentation \u3e22.5-deg angular separation, centered directly on the opposite side of the animal with long working distance pickup,7 allowing noncontact measurement of the diffuse light through the animal. The diffuse intensity signals collected at each of the five channels were then translated via 400-μm role= presentation \u3e400-μm fibers and split using beamsplitters to be directed toward the fluorescence (95%) and transmission (5%) channel detectors. A 650-nm role= presentation \u3e650-nm long-pass filter was used in the fluorescence channels to isolate the signal, and in the transmitted intensity signals, a neutral density filter (2 OD) was used to attenuate the signals. This latter filtering was necessary to ensure that the fluorescence and transmission. Intensity signals fell within the same dynamic range, allowing a single 1s role= presentation \u3e1s acquisition for each detector. Scans were then performed by rotating the fan-beam around the specimen to 32 locations. A GE eXplore Locus SP scanner (GE Healthcare, London, Ontario, Canada) that incorporated a detector with 94-micronpixel role= presentation \u3e94-micronpixel resolution, a 80-kV role= presentation \u3e80-kV peak voltage, and a tube current of 450μAs role= presentation \u3e450μAs , was used in acquiring the microCT data, as displayed in Fig. 2 . In this example, since soft tissue was being imaged, the CT data was largely used to image the exterior of the animal, although in future studies, it could be used to isolate the cranium region as well

Five High-Redshift Quasars Discovered in Commissioning Imaging Data of the Sloan Digital Sky Survey

We report the discovery of five quasars with redshifts of 4.67 - 5.27 and z'-band magnitudes of 19.5-20.7 M_B ~ -27. All were originally selected as distant quasar candidates in optical/near-infrared photometry from the Sloan Digital Sky Survey (SDSS), and most were confirmed as probable high-redshift quasars by supplementing the SDSS data with J and K measurements. The quasars possess strong, broad Lyman-alpha emission lines, with the characteristic sharp cutoff on the blue side produced by Lyman-alpha forest absorption. Three quasars contain strong, broad absorption features, and one of them exhibits very strong N V emission. The amount of absorption produced by the Lyman-alpha forest increases toward higher redshift, and that in the z=5.27 object (D_A ~ 0.7) is consistent with a smooth extrapolation of the absorption seen in lower redshift quasars. The high luminosity of these objects relative to most other known objects at z >~ 5 makes them potentially valuable as probes of early quasar properties and of the intervening intergalactic medium.Comment: 13 pages in LaTex format, two postscirpt figures. Submitted to the Astronomical Journa

KL Estimation of the Power Spectrum Parameters from the Angular Distribution of Galaxies in Early SDSS Data

We present measurements of parameters of the 3-dimensional power spectrum of galaxy clustering from 222 square degrees of early imaging data in the Sloan Digital Sky Survey. The projected galaxy distribution on the sky is expanded over a set of Karhunen-Loeve eigenfunctions, which optimize the signal-to-noise ratio in our analysis. A maximum likelihood analysis is used to estimate parameters that set the shape and amplitude of the 3-dimensional power spectrum. Our best estimates are Gamma=0.188 +/- 0.04 and sigma_8L = 0.915 +/- 0.06 (statistical errors only), for a flat Universe with a cosmological constant. We demonstrate that our measurements contain signal from scales at or beyond the peak of the 3D power spectrum. We discuss how the results scale with systematic uncertainties, like the radial selection function. We find that the central values satisfy the analytically estimated scaling relation. We have also explored the effects of evolutionary corrections, various truncations of the KL basis, seeing, sample size and limiting magnitude. We find that the impact of most of these uncertainties stay within the 2-sigma uncertainties of our fiducial result.Comment: Fig 1 postscript problem correcte

The SEGUE Stellar Parameter Pipeline. I. Description and Initial Validation Tests

We describe the development and implementation of the SEGUE (Sloan Extension for Galactic Exploration and Understanding) Stellar Parameter Pipeline (SSPP). The SSPP derives, using multiple techniques, radial velocities and the fundamental stellar atmospheric parameters (effective temperature, surface gravity, and metallicity) for AFGK-type stars, based on medium-resolution spectroscopy and $ugriz$ photometry obtained during the course of the original Sloan Digital Sky Survey (SDSS-I) and its Galactic extension (SDSS-II/SEGUE). The SSPP also provides spectral classification for a much wider range of stars, including stars with temperatures outside of the window where atmospheric parameters can be estimated with the current approaches. This is Paper I in a series of papers on the SSPP; it provides an overview of the SSPP, and initial tests of its performance using multiple data sets. Random and systematic errors are critically examined for the current version of the SSPP, which has been used for the sixth public data release of the SDSS (DR-6).Comment: 64 pages, 8 tables, 12 figures, submitted to the Astronomical Journa

The Angular Correlation Function of Galaxies from Early SDSS Data

The Sloan Digital Sky Survey is one of the first multicolor photometric and spectroscopic surveys designed to measure the statistical properties of galaxies within the local Universe. In this Letter we present some of the initial results on the angular 2-point correlation function measured from the early SDSS galaxy data. The form of the correlation function, over the magnitude interval 18<r*<22, is shown to be consistent with results from existing wide-field, photographic-based surveys and narrower CCD galaxy surveys. On scales between 1 arcminute and 1 degree the correlation function is well described by a power-law with an exponent of ~ -0.7. The amplitude of the correlation function, within this angular interval, decreases with fainter magnitudes in good agreement with analyses from existing galaxy surveys. There is a characteristic break in the correlation function on scales of approximately 1-2 degrees. On small scales, < 1', the SDSS correlation function does not appear to be consistent with the power-law form fitted to the 1'< theta <0.5 deg data. With a data set that is less than 2% of the full SDSS survey area, we have obtained high precision measurements of the power-law angular correlation function on angular scales 1' < theta < 1 deg, which are robust to systematic uncertainties. Because of the limited area and the highly correlated nature of the error covariance matrix, these initial results do not yet provide a definitive characterization of departures from the power-law form at smaller and larger angles. In the near future, however, the area of the SDSS imaging survey will be sufficient to allow detailed analysis of the small and large scale regimes, measurements of higher-order correlations, and studies of angular clustering as a function of redshift and galaxy type