bluuebunny/crossref_metadata_2025 huggingface dataset:
Tomographic imaging in hydrocarbon reservoirs
Authors: Justice J. H. , Vassiliou A. A. , Singh S. , Logel J. D. , Hansen P. A. , Hall B. R. , Hutt P. R. , Solanki J. J.
Published: March 2007

Clastic reservoirs saturated with heavy oils have been observed to exhibit a marked relationship between velocity of propagation of acoustic waves and changes introduced by certain kinds of enhanced oil recovery procedures, including heating of the reservoir. This observation forms the basis for a method of monitoring the changes which occur in the reservoir when these enhanced oil recovery (EOR) procedures are used. New developments in diffraction tomographic imaging allow accurate, high‐resolution images to be obtained in hydrocarbon reservoirs, clearly delineating the zones affected by these enhanced oil recovery procedures. When both compressional and shear wave data can be obtained, additional physical parameters such as Poissons ratio can be reconstructed.
Algebraic methods in 3‐d motion estimation from two‐view point correspondences
Authors: Netravali A. N. , Huang T. S. , Krishnakumar A. S. , Holt R. J.
Published: March 2007

We consider the problem of determining motion (3‐D rotation and translation) of rigid objects from their images taken at two time instants. We assume that the locations of the perspective projection on the image plane of n points from the surface of the rigid body are known at two time instants. For n = 5, we show that there are at most ten possible motion values (in rotation and translation) and give many examples. For n ≥ 6, we show that the solution is generally unique. We derive a variety of necessary and sufficient conditions a solution must satisfy, show their equivalence, and use algebraic geometry to derive the bound on the number of solutions. A homotopy method is then used to compute all the solutions. Several examples are worked out and our computational experience is summarized.
On a problem in radiotherapy: Questions of non‐negativity
Authors: Cormack A. M. , Quinto Eric Todd
Published: March 2007

A well‐known result is used to show that if g is a non‐negative function and the radiation field, f, is its Radon transform, the dose field, f̂, is the convolution of g with (1/πr) and is necessarily non‐negative. Simple series expansions of f and f̂ are given, and the series for f is written as a finite Fourier series. Known properties of finite Fourier series are used to seek, fruitlessly, for useful conditions on the coefficients to ensure the non‐negativity of f.
New spherical PET design with fresnel aperture orientation
Authors: Cho Z. H. , Kim Y. S. , Hilal S. K. , Kim Y. H.
Published: March 2007

A new spherical PET using Fresnel aperture is being designed, and construction is in progress. In the new design, the original spherical geometry is modified to accommodate a more flexible gantry construction and data processing while preserving the focused geometry of the original design. The performance of this new Fresnel aperture‐SPET (F‐SPET) is expected to follow closely with that of the original S‐PET design. An analysis of an F‐SPET designed with nine modular layers, with each modular layer being four rings, was performed in terms of the counting statistics and solid angle and compared with the original S‐PET as well as the conventional cylindrical PET. According to the simulation results, the sensitivity gain of the Fresnel aperture‐SPET remains a factor of 2 over the equivalent cylindrical system and has nearly the same performance as the original S‐PET, while offering a simpler means in construction and data handling for the image reconstruction.
The nuclear magnetic resonance imaging of short t2 material using solid echoes
Authors: Attard J. J. , McDonald P. J.
Published: March 2007

The application of solid echoes to the nuclear magnetic resonance (NMR) imaging of short T2 materials is demonstrated by means of two‐dimensional (19F) images. A closed‐form, exact and generally applicable expression for solid echo imaging is derived and a procedure for on‐the‐fly data analysis given.
Beam profiling by vibrating knife edge: Implications for near‐field optical scanning microscopy
Authors: Korpel A. , Mehrl D. J. , Samson S.
Published: March 2007

We show theoretically and experimentally that beam profiling with a vibrating knife exhibits spatial resolution equal to the knife‐edge excursion. We discuss the implications of this for near‐field optical scanning microscopy, propose an extension of the method to two dimensions, and calculate impulse response, step response, and spatial frequency response.
Microwave imaging of moving objects
Authors: Li Hsueh‐Jyh , Yang Sheng‐Hui , Liu Ta‐Yung , Yen Shih‐Liang , Shen Yuhsyen , Farhat Nabil H.
Published: March 2007

Microwave images for objects in motion can be obtained with quality as good as those obtained in the stationary case if the signal waveforms, data acquisition systems, and image reconstruction algorithms are cleverly designed. The principle of imaging for objects in motion is to eliminate the gross Doppler effect of the echo signals and only reserve the differential Doppler information to reconstruct the image. Accordingly, requirements for parameters of the signal waveform are established. Two steps are involved in the image reconstruction algorithm: range alignment and phase compensation. Focused images of complex‐shaped targets with simulated motion have been obtained experimentally.
Visible and infrared mapping spectrometer for exploration of comets, asteroids, and the saturnian system of rings and moons
Authors: Juergens David W. , Duval James E. , Lockhart Robert F. , Langevin Yves , Formisano Vittorio , Bellucci Giancarlo
Published: March 2007

The science objectives and system design for a Visible and Infrared Mapping Spectrometer (VIMS), an imaging spectrometer for planetary exploration, are described. The instrument development is the result of a collaboration between scientists and engineers from the United States, Italy, and France. NASA has selected VIMS as a facility instrument for the Comet Rendezvous Asteroid Flyby (CRAF) Mission, and as a candidate facility instrument for the Cassini Mission to explore Saturn and its rings and moons. (A facility instrument is provided by the project for the use of a science team which was selected on the basis of individual competitive science proposals.) VIMS covers the spectral range from 0.35 to 5.2 μm with a nominal spatial resolution of 0.5 milliradians (pixel size) and spectral resolutions (spectral width) of 7 nm at 0.35–1.0‐ μm wavelength and 16nm at 1.0–5.2‐μm wavelength. The nominal pixel size is 0.5 × 0.5 mrad2. The two separate missions are scheduled to be launched by NASA from the Eastern Test Range at Cape Canaveral, Florida, using the Titan IV Launch Vehicle. The planned launch date for the Cassini Mission is November 1995. The planned launch date for the CRAF Mission is February 1996.
Moderate resolution imaging spectrometer‐tilt (modis‐t)
Authors: Magner Thomas J. , Salomonson V. V.
Published: March 2007

The Moderate Resolution Imaging Spectrometer‐Tilt (MODIS‐T) instrument is being constructed for flight on the Earth Observing System (EOS). It is an imaging spectrometer utilizing a grating‐type, reflecting Schmidt optical design that must provide a 1.1‐km spatial resolution at nadir from a spacecraft altitude of 705 km with a 1500‐km cross‐track swath and a ±50° fore and aft tilt capability. The instrument is required to cover the wavelength range from 400 to 880 nm in approximately 15‐nm steps with less than 2.3% instrument‐induced polarization. The absolute radiometric accuracy must be at least 5% over the full dynamic range of the instrument.
Spaceborne imaging radars
Authors: Elachi Charles
Published: March 2007

The Seasat and Shuttle imaging radars flown in the 1970s and 1980s established a strong scientific and technical base for a number of imaging radars that are flying or under development. Recent advances in understanding wave‐surface interactions, utilization of multispectral and polarimetric data, as well as advances in microwave and electronic technology, are allowing the development of a new generation of multiparameter imaging radars that will allow quantitative measurements of surface and near‐surface geophysical parameters and monitoring of surface processes over long‐term duration. This article is an overview of spaceborne imaging radars presently flying or under development.
Character recognition via critical points
Authors: Shchepin E. V. , Nepomnyashchii G. M.
Published: March 2007

A new approach to image coding, based on ordinate‐preserving plane homoeomorphism invariants, is presented. A critical‐points graph bearing full information on these invariants is outlined. Appropriate noise‐smoothing techniques are developed. The proposed method has been implemented and tested with a new optical character recognition program, CRIPT.
Comparison of the born iterative method and tarantola's method for an electromagnetic time‐domain inverse problem
Authors: Moghaddam M. , Chew W. C. , Oristaglio M.
Published: March 2007

Two methods of solving the nonlinear two‐dimensional electromagnetic inverse scattering problem in the time domain are considered. These are the Born iterative method and the method originally proposed by Tarantola for the seismic reflection inverse problems. The former is based on Born‐type iterations on an integral equation, whereby at each iteration the problem is linearized, and its solution is found via a regularized optimization. The latter also uses an iterative method to solve the nonlinear system of equations. Although it linearizes the problem at each stage as well, no optimization is carried out at each iteration; rather the problem as a whole is posed as a (regularized) optimization. Each method is described briefly and its computational complexity is analyzed. Tarantola's method is shown to have a lower numerical complexity compared to the Born iterative method for each iteration, but in the examples considered, required more iterations to converge. Both methods perform well when inverting a smooth profile; however, the Born iterative method gave better results in resolving localized point scatterers.
Data processing system for nuclear medicine images
Authors: Kuba A. , Makay A. , Máté E. , Csernay L.
Published: March 2007

A software system (MicroSegams) is described which is able to acquire, store, present, and process nuclear medicine images. The most important basic procedures (e.g., image acquisition from a gamma camera, selection of a study from the catalogue, drawing regions of interest, etc.) and complete clinical procedures (e.g., renography, brain perfusion, etc.) can be activated directly from the system menu by mouse. The language sLan (a subset of programming language C containing more than 200 elementary functions) can also be used to write new procedures to be interpreted or compiled. The system is offered as a basic tool for the performance of static, dynamic, gated, or tomographic investigations in clinical practice.
A fourier‐transforming coded aperture
Authors: Patt B. E. , Wade G. , Richardson J. M.
Published: March 2007

A Fourier‐transforming coded aperture can be synthesized with a pair of two‐dimensional detector arrays, each preceded by a properly designed sequence of two Gabor‐zone plates. The coded image falling on one of the arrays corresponds to the cosine transform of the object. The coded image falling on the other array corresponds to the sine transform. Thus the Fourier transform of the object can be formed by using the first coded image as the real part, and the second coded image as the imaginary part, of the Fourier transform. Fourier‐transforming coded apertures of this type are capable of producing better resolution than spatial‐domain apertures. Although the system described in this article is specifically applied to a gamma‐ray camera, such a system is generally applicable to a wide varioty of noncoherent imagers.©1993 John Wiley & Sons Inc
Self‐calibration of large phased‐array antennas for radar
Authors: Steinberg Bernard D.
Published: March 2007

Self‐calibration of a phased antenna array is required when distortions in the array are not known a priori and cannot be measured, or when turbulence in the propagation medium perturbs the radiation field. Two types of self‐calibration procedures are discussed that have proved successful in experimental high‐resolution two‐dimensional microwave radar imaging. Each extracts information from the backscattered reradiation field to deduce a compensating weight vector for the phased array antenna. The first depends upon the presence of a strong reflector in the field of view of the transmitter. The second calibrates the array from correlation estimates of wavefront samples in the array. The basic algorithm in each group is described, along with two more sophisticated algorithms in the latter class. Two‐dimensional radar images of airplanes are shown with resolution comparable to human vision. The performance of each algorithm and comparisons between them are illustrated by these images of targets and by simulation experiments.©1993 John Wiley & Sons Inc
A status report on applying discrete inverse theory to ionospheric tomography
Authors: Fremouw E. J. , Secan J. A. , Bussey R. M. , Howe B. M.
Published: March 2007

Discrete inverse theory (DIT) provides an orderly framework in which to combine measurements of total electron content (TEC) with a priori information to image the ionosphere tomographically. We have developed a DIT‐based tomographic processor for use with relative TEC data. The processor's a priori information comprises the global mean of over 17,000 profiles generated from an ionospheric model, for use as a “generic background”; empirical orthogonal functions (EOFs) spanning the same model profiles, for use as vertical basis functions; and a red power‐law horizontal spectrum. Relative TEC data are used to evaluate coefficients multiplying the EOFs and harmonics, thus quantifying a perturbation electron‐density field. The perturbation field, which need not be small, is added to the a priori background to produce the image. We present here several images produced by employing the processor with simulated TEC data based on in situ ionospheric measurements and incoherent‐scatter radar observations.©1994 John Wiley & Sons Inc
Few‐field radiation therapy optimization in the phase space of complication‐free tumor control
Authors: Söderström Svante , Gustafsson Anders , Brahme Anders
Published: March 2007

The phase space of P+, describing the probability of achieving tumor control without causing severe complications in normal tissues, has been investigated for three different clinically relevant treatment geometries. These include tumors in the head and neck region, thorax, and pelvis. Some general conclusions about the shape and properties of the P+ phase space are given for the selected target volumes. The use of three different radiation beam types‐strictly homogeneous, wedged, and generally nonuniform beams‐has been investigated and the considerable differences in the P+ phase space are shown. One conclusion is that the exact selection of beam entry direction becomes gradually less important as the number of beam portals becomes larger. One of the most important results is that use of appropriately selected nonuniform beam profiles reduces the number of necessary beam portals to such a low level that the treatment technique becomes simple and reliable at the same time as the probability of achieving tumor control without severe complications is almost as high as with an unlimited number of beams This means that most ordinary treatment units equipped with beam compensating filters can be used for closely optimal radiation therapy.
Effects of biophysical and physiologic parameters on brain activation‐induced R2* and R2 changes: Simulations using a deterministic diffusion model
Authors: Bandettini Peter A. , Wong Eric C.
Published: March 2007

A central issue in magnetic resonance imaging of human brain function using blood oxygenation level‐dependent (BOLD) contrast is the accurate interpretation of the signal changes that are observed. Using a method that incorporates repeated phase rotation and convolution with a smoothing function to simulate spin diffusion in the presence of magnetic field perturbers, the dependencies of the absolute and relative changes in transverse relaxation rates (δR2* and δR2) on biophysical and physiologic parameters were explored. First we introduce the modeling methodology. Then we simulate δR2* and δR2 as physiologic and biophysical parameters are modulated within the ranges that they vary across subjects and voxels in the brain. The simulations demonstrate that the δR2* and δR2 values that occur with activation‐induced changes in blood oxygenation depend most strongly on the resting state blood volume and field strength. The δR2*/δR2 ratios depend most strongly on the vessel radius and spin diffusion coefficient.
In vivo validation of the bold mechanism: A review of signal changes in gradient echo functional MRI in the presence of flow
Authors: Haacke E. Mark , Lai Song , Yablonskiy Dmitriy A. , Lin Weili
Published: March 2007

Brain functional magnetic resonance imaging (FMRI) is possible because of local changes in blood flow and oxygenation levels. Understanding the role of each mechanism is important for interpreting FMRI results as well as for the design of the experiment itself. In this review, we address the role of flow and blood oxygen level dependence (BOLD) and how they can be used in conjunction with each other to enhance the BOLD effect. We also discuss the role of intra/extravascular signal changes in the presence of a vessel for the imaging situation and show how the ratio of these two contributions is likely to change as the blood volume fraction changes. Using the BOLD model itself, along with 3‐D phase imaging, we show that blood oxygenation level in veins in vivo is Y = 0.544 ± 0.029 as measured in 14 vessels in five subjects. Finally, we comment on the use of phase images themselves as a means to discriminate tissues with different levels of blood such as gray matter, white matter, and cerebrospinal fluid.
Susceptibility effect‐enhanced functional MR imaging using tailored RF gradient echo (TRFGE) sequence
Authors: Cho Z. H. , Ro Y. M. , Chung S. C.
Published: March 2007

In this article, we have described a tailored radio frequency gradient echo (TRFGE) technique which is applied to functional imaging. The TRFGE technique is insensitive to the inflow effect, which often complicates the analysis of functional magnetic resonance imaging (FMRI) data, and is also insensitive to nonfunctional backgrounds such as static tissues. The susceptibility effect measurement obtained from the TRFGE technique therefore provides a unique form of functional imaging, namely, susceptibility‐only functional imaging. To examine TRFGE functional imaging systematically, we designed an experiment to determine the flow effect and susceptibility‐dependent signal change by varying the imaging parameters including flip angle α, repetition time TR, and echo time TE. The results obtained were then compared with the data obtained with conventional gradient‐echo (CGE) functional MR imaging. The experimental results shown were all obtained using human volunteers with a 2.0‐T whole‐body MRI system.
Acquisition and reconstruction of the principal components of an image: A novel MRI technique for reducing scanning time
Authors: Cao Yue , Levin David N.
Published: March 2007

This article describes a novel MRI technique as well as its variant, which use prior knowledge to acquire and reconstruct the principal components of an image to reduce scanning time. Examples in the application of this technique are given. The implications of these results and the potential in the application of the functional imaging are discussed.
Functional MRI of human motor cortices during overt and imagined finger movements
Authors: Kim Seong‐Gi , Jennings Jonathan E. , Strupp John P. , Andersen Peter , Uǧurbil Kâmil
Published: March 2007

A T2*‐weighted echo‐planar imaging technique at 4 T was employed to produce functional maps of the human motor cortices during overt and imagined movements. Tasks required subjects either to perform or imagine a visually cued sequence of digit‐to‐thumb oppositions. The following significant functional changes were observed: (1) Contralateral primary motor cortex showed attenuated activity during the imagined tasks; (2) bilateral supplementary motor area and premotor cortices were active during both the visually instructed movements and the imagined finger movements; and (3) superior parietal cortex showed varying degrees of activation in subjects performing the movement and imagined tasks. In preliminary data, task‐related activation of the primary motor cortex during imagined finger movements was observed in all subjects, suggesting that the motor cortex may indeed have “premotor” functions in addition to its classically assigned function solely as a muscle controller.
Occamian approach in the image restoration and other inverse problems
Authors: Terebizh V. Yu.
Published: March 2007

A non‐Bayesian approach to inverse problems is discussed in terms of the image restoration problem. The approach is based on the extended notion of the feasible estimate and on the Occam's principle of choosing the simplest object, consistent with the data. The Occamian estimation is performed by transforming the inverse or maximum likelihood estimate to its principal components, which are induced by Fisher's information matrix.
Osteoblast response to fluid induced shear depends on substrate microarchitecture and varies with time
Authors: Schwartz Z. , Denison T.A. , Bannister S.R. , Cochran D.L. , Liu Y.H. , Lohmann C.H. , Wieland M. , Boyan B.D.
Published: March 2007

Osteoblasts are exposed to fluid shear in vivo but the effects are not well understood, particularly how substrate properties or length of exposure modify the response. Short exposure (1 h) to shear reduces the stimulatory effect of micron‐scale surface structure on osteoblast differentiation, but the effects of longer term exposures are not known. To test the hypothesis that substrate‐dependent responses of osteoblasts to shear depend on the length of exposure to fluid flow, MG63 osteoblasts were grown on tissue culture glass, which has an average roughness (Ra) < 0.2 μm; machined Ti disks (PT, Ra < 0.6 μm); Ti disks with a complex microarchitecture [sand blasted acid etched (SLA), Ra = 4–5 μm); and Ti plasma‐sprayed surfaces [Ti via plasma spray (TPS), Ra = 7 μm]. Confluent cultures were exposed to pulsatile flow at shear forces of 0, 1, and 14 dynes/cm2 for 0, 6, 12, and 24 h. Shear reduced cell number on all surfaces, with greatest effects on TPS. Shear had no effect on alkaline phosphatase on smooth surfaces but increased enzyme activity on SLA and TPS in a time‐dependent manner. Its effects on osteocalcin, TGF‐β1, and PGE2 in the conditioned media were greatest on these surfaces as well. Responses to fluid‐induced shear were blocked by the general Cox inhibitor indomethacin and the Cox‐2 inhibitor meloxicam, indicating that response to shear is mediated by prostaglandin produced via a Cox‐2 dependent mechanism. These results show that the effects of fluid induced shear change with time and are substrate dependent, suggesting that substrate microarchitecture regulates the osteoblast phenotype and effects of shear are determined by the maturation state of the responding population. © 2007 Wiley Periodicals, Inc. J Biomed Mater Res, 2007
Anti‐proliferative effects of evodiamine on human prostate cancer cell lines DU145 and PC3
Authors: Kan Shu‐Fen , Yu Ching‐Han , Pu Hsiao‐Fung , Hsu Jong‐Ming , Chen Ming‐Jen , Wang Paulus S.
Published: March 2007

Prostate carcinoma is one of the most common malignant tumors and has become a more common cancer in men. Previous studies demonstrated that evodiamine (EVO) exhibited anti‐tumor activities on several cancers, but its effects on androgen‐independent prostate cancer are unclear. In the present study, the action mechanisms of EVO on the growth of androgen‐independent prostate cancer cells (DU145 and PC3 cells) were explored. EVO dramatically inhibited the growth and elevated cytotocixity of DU145 and PC3 cells. The flow cytometric analysis of EVO‐treated cells indicated a block of G2/M phase and an elevated level of DNA fragmentation. The G2/M arrest was accompanied by elevated Cdc2 kinase activity, an increase in expression of cyclin B1 and phosphorylated Cdc2 (Thr 161), and a decrease in expression of phosphorylated Cdc2 (Tyr 15), Myt‐1, and interphase Cdc25C. TUNEL examination showed that EVO‐induced apoptosis was observed at 72 h. EVO elevated the activities of caspase 3, 8, and 9 in DU145 cells, while in PC3 cells only the activities of caspase 3 and 9 were elevated. EVO also triggered the processing of caspase 3 and 9 in both DU145 and PC3 cells. We demonstrate that roscovitine treatment result in the reversion of G2/M arrest in response to EVO in both DU145 and PC3. However, inhibitory effect of roscovitine on EVO‐induced apoptosis could only be observed in DU145 rather than PC3. In DU145, G2/M arrest might be a signal for initiation of EVO‐triggered apoptosis. Whereas EVO‐triggered PC3 apoptosis might be independent of G2/M arrest. These results suggested that EVO inhibited the growth of prostate cancer cell lines, DU145 and PC3, through an accumulation at G2/M phase and an induction of apoptosis. J. Cell. Biochem. 101: 44–56, 2007. © 2007 Wiley‐Liss, Inc.
TIMP‐1 regulates cell proliferation by interacting with the ninth zinc finger domain of PLZF
Authors: Rho Seung Bae , Chung Bo Mee , Lee Je‐Ho
Published: March 2007

The tissue inhibitors of metalloproteinases (TIMPs) are multifunctional proteins that specifically inhibit matrix metalloproteinases (MMPs) and regulate extracellular matrix (ECM) turnover and tissue remodeling. This is directed by forming tightly bound inhibitory complexes with MMPs. Recent years have revealed important differences of various biological activities between TIMP families but molecular mechanisms are not clear. To define the molecular mechanisms of TIMP‐1‐dependent biological processes, we used TIMP‐1 as bait in a yeast two‐hybrid screen, along with a human ovary cDNA library. Further characterization revealed the ninth zinc finger domain as an interacting domain of the promyelocytic leukemia zinc finger protein (PLZF). Interaction of PLZF with TIMP‐1 in mammalian cells was also confirmed by co‐immunoprecipitation and with in vitro binding assays. We investigated whether TIMP‐1‐mediated anti‐apoptotic activity could promote the growth of ovarian cancer in an experimental model system. TIMP‐1 treatment was found to be more effective at increasing ovarian cancer growth when compared with PLZF in parallel experiments. Subsequently, the efficacy of a combined treatment with TIMP‐1 and PLZF was investigated. In the presence of both of these proteins, TIMP‐1 significantly reduced apoptosis induced by PLZF in cervical carcinoma cells. These combined results indicate that TIMP‐1 functions as an anti‐activator of the transcriptional repressive activity of PLZF. J. Cell. Biochem. 101: 57–67, 2007. © 2007 Wiley‐Liss, Inc.
Evidence for the existence of satellite DNA‐containing connection between metaphase chromosomes
Authors: Kuznetsova I.S. , Enukashvily N.I. , Noniashvili E.M. , Shatrova A.N. , Aksenov N.D. , Zenin V.V. , Dyban A.P. , Podgornaya O.I.
Published: March 2007

Physical connections between mitotic chromosomes have been reported previously. It was assumed that the interchromosome connection was based on the DNA‐protein thread. However, the data about DNA sequences and protein component in the thread is fragmentary. We demonstrated on the mouse cultured cell line and prematurely condensed chromosomes that: (a) all four mouse satellite DNA fragments (major and minor satellite, mouse satellite 3 (MS3) and mouse satellite 4 (MS4)) were involved in the thread formation; (b) MS4 was involved in the thread to the least extent among all the other fragments; (c) telomere was never a member of the thread; (d) the thread was synthesized at a late G2 phase; (e) RNA helicase p68 and CENP‐B were among the protein components of the interchromosome connection. It was shown by FACS analysis that in mouse and human cell lines: (1) the flow karyotype spectrums were never free from chromosome aggregates; (2) chromosome association did not depend on the chromosome length and each chromosome was free to associate with the other. J. Cell. Biochem. 101: 1046–1061, 2007. © 2007 Wiley‐Liss, Inc.
Angiotensin converting enzyme 2 is primarily epithelial and is developmentally regulated in the mouse lung
Authors: Wiener Renda Soylemez , Cao Yu Xia , Hinds Anne , Ramirez Maria I. , Williams Mary C.
Published: March 2007

Angiotensin converting enzyme (ACE) 2 is a carboxypeptidase that shares 42% amino acid homology with ACE. Little is known about the regulation or pattern of expression of ACE2 in the mouse lung, including its definitive cellular distribution or developmental changes. Based on Northern blot and RT‐PCR data, we report two distinct transcripts of ACE2 in the mouse lung and kidney and describe a 5′ exon 1a previously unidentified in the mouse. Western blots show multiple isoforms of ACE2, with predominance of a 75–80 kDa protein in the mouse lung versus a 120 kDa form in the mouse kidney. Immunohistochemistry localizes ACE2 protein to Clara cells, type II cells, and endothelium and smooth muscle of small and medium vessels in the mouse lung. ACE2 mRNA levels peak at embryonic day 18.5 in the mouse lung, and immunostaining demonstrates protein primarily in the bronchiolar epithelium at that developmental time point. In murine cell lines ACE2 is strongly expressed in the Clara cell line mtCC, as opposed to the low mRNA expression detected in E10 (type I‐like alveolar epithelial cell line), MLE‐15 (type II alveolar epithelial cell line), MFLM‐4 (fetal pulmonary vasculature cell line), and BUMPT‐7 (renal proximal tubule cell line). In summary, murine pulmonary ACE2 appears to be primarily epithelial, is developmentally regulated, and has two transcripts that include a previously undescribed exon. J. Cell. Biochem. 101:1278–1291, 2007. © 2007 Wiley‐Liss, Inc.
Antiproliferative activity of CCN3: Involvement of the C‐terminal module and post‐translational regulation
Authors: Bleau A.M. , Planque N. , Lazar N. , Zambelli D. , Ori A. , Quan T. , Fisher G. , Scotlandi K. , Perbal B.
Published: March 2007

Previous work had suggested that recombinant CCN3 was partially inhibiting cell proliferation. Here we show that native CCN3 protein secreted into the conditioned medium of glioma transfected cells indeed induces a reduction in cell proliferation. Large amounts of CCN3 are shown to accumulate both cytoplasmically and extracellularly as cells reach high density, therefore highlighting new aspects on how cell growth may be regulated by CCN proteins. Evidence is presented establishing that the amount of CCN3 secreted into cell culture medium is regulated by post‐translational proteolysis. As a consequence, the production of CCN3 varies throughout the cell cycle and CCN3 accumulates at the G2/M transition of the cycle. We also show that CCN3‐induced inhibition of cell growth can be partially reversed by specific antibodies raised against a C‐terminal peptide of CCN3. The use of several clones expressing various portions of CCN3 established that the CT module of CCN3 is sufficient to induce cell growth inhibition. J. Cell. Biochem. 101: 1475–1491, 2007. © 2007 Wiley‐Liss, Inc.
Mitochondrial‐targeted active Akt protects SH‐SY5Y neuroblastoma cells from staurosporine‐induced apoptotic cell death
Authors: Mookherjee Paramita , Quintanilla Rodrigo , Roh Myoung‐Sun , Zmijewska Anna A. , Jope Richard S. , Johnson Gail V.W.
Published: March 2007

Akt is a serine/threonine protein kinase that plays a vital role in promoting cellular survival. Predominantly cytosolic, upon stimulation with growth‐factors or stress, active Akt translocates into mitochondria, but the functions of Akt in mitochondria are not yet fully understood. Mitochondria play a central role in apoptotic pathways and given Akt's functions in the cytoplasm, Akt in mitochondria may help preserve mitochondrial integrity during cellular stress. To test if the translocation of Akt into mitochondria is neuroprotective, adenoviral vectors expressing a constitutively active Akt, Ad‐HA‐Akt (DD), and a constitutively active Akt with a mitochondrial targeting signal, Ad‐Mito‐HA‐Akt (DD), were generated. Human SH‐SY5Y neuroblastoma cells expressing the adenoviral constructs were treated with staurosporine to initiate intrinsic apoptotic cell death and several aspects of the mitochondrial apoptotic pathway were evaluated. Expression of active Akt targeted to mitochondria was found to be sufficient to significantly reduce staurosporine‐induced activation of caspase‐3 and caspase‐9, the release of cytochrome c from mitochondria, and Bax oligomerization at mitochondria. These findings demonstrate that intramitochondrial active Akt results in efficient protection against apoptotic signaling. J. Cell. Biochem. 102: 196–210, 2007. © 2007 Wiley‐Liss, Inc.
Computational tool to model the packing of polycyclic chains: Structural analysis of amorphous polythiophene
Authors: Curcó David , Alemán Carlos
Published: March 2007

A very efficient computational procedure, which was previously developed to generate and relax atomistic models of linear and comb‐like amorphous polymers, has been adapted to model the amorphous phase of polycyclic systems. The strategy, which is a based in a generation algorithm that eliminates the torsion strain and a simple Monte Carlo Metropolis method to relax the generated structures, has been used to predict the density of amorphous polythiophene by combining NVT and NPT simulations. The theoretical value is in the excellent agreement with the experimental one, the former being overestimated by only 3–5%. Next, the molecular conformation and the packing of the rings were studied in detail. Interestingly, the amorphous phase of polythiophene can be described as a packing of elongated molecular chains more or less aligned in the same direction, in which the thiophene rings close in the space but belonging to different chains tend to adopt approximate parallel or antiparallel displaced π‐stacked arrangements. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
A simple procedure for the rapid immunofluorescence staining of human tumor antigens with human monoclonal antibodies
Authors: Glassy Mark C , Gaffar S. A.
Published: March 2007

A novel technique employed in preparing slides used for immunofluorescence staining of human tumor antigens with human anti‐cancer monoclonal antibodies is described. The anchorage of the cancer cells to the plastic substratum is used as a basis in eliminating cell fixation by physical and chemical procedures. In this method, the bottoms of the tissue culture flasks with the adherent A431 cell line, a carcinoma of the vulva, were cut into slides of 2 × 6 cm. This antigen‐positive target cell was then reacted with the VLN3G2 monoclonal IgG antibody and with the fluorescein‐labeled F(ab′)2 of goat anti‐human IgG. Most A431 cells demonstrated intense fluorescence staining while others exhibited diffuse and often discontinuous membrane staining with the antibodies. In summary, this simplistic technique can be applied for the rapid detection of antigens displayed by the adherent tumor cell lines.
Synthetic peptide derived from the epstein‐barr virus encoded early diffuse antigen (ea‐d) reactive with human antibodies
Authors: Fox Robert I. , Scott Susan , Houghten Richard , Whalley Alice , Geltofsky Jack , Vaughan John , Smith Richard
Published: March 2007

Primary infection with Epstein‐Barr virus (EBV) and reactivation of latent virus are associated with increased antibody titers against the diffuse early antigen (EA‐D). In order to better define the antigenic epitopes recognized by antibodies from patients with infectious mononucleosis (IM) and with other disease states, a series of synthetic peptides were prepared based on the DNA sequence encoding the EA‐D molecule. One synthetic peptide (K7b) was reactive with the majority of sera from patients with acute IM. Anti‐K7b activity was most readily detected among IgM and IgA antibodies and to a lesser extent among IgG antibodies. In contrast, significant elevations of anti‐K7b activity were observed in less than 5% of healthy adults. Serial analysis of samples from individuals prior to and after exposure to EBV demonstrated increased anti‐K7b reactivity associated with the symptoms of acute IM. Elevated anti‐peptide K7b titers also were found in sera of patients with nasopharyngeal carcinoma and with Sjogren's syndrome (an autoimmune disease involving the salivary glands). Four different synthetic peptides from other regions of the EA‐D molecule were not reactive with antibodies from these patients nor from IM patients. These results suggest that peptide K7b defines an antigenic epitope recognized during primary EBV infection and during viral reactivation occurring in patients with autoimmune and neoplastic disease.
Simultaneous measurement of serum retinol, tocopherols, carotenes, and carotenoids by high performance liquid chromatography
Authors: Kaplan L. A. , Miller J. A. , Stein E. A.
Published: March 2007

An isocratic, high‐performance liquid chromatography method is presented for the simultaneous analysis of retinol, tocopherols, carotenes, and other carotenoids. The method employs detection at two wavelengths (292 and 450 nm) and three internal standards, which are: retinyl acetate, alpha‐tocopheryl acetate, and retinyl palmitate. The use of the internal standards is important for accurate quantitation, especially to correct for recovery of beta‐carotene. The long‐term (n = 81, over three months) precision of the method ranged from a coefficient of variation of 8.2% for retinol to 16% for lycopene. This assay system provides accurate, precise, and rapid analysis and is suitable for longitudinal and cross‐sectional large‐scale epidemiological studies of these vitamins.
Serologic and cellular assays to monitor therapy with murine monoclonal antibodies
Authors: Shawler Daniel L. , McCallister Tammy J. , Sobol Robert E. , Dillman Robert O.
Published: March 2007

The emergence of new therapeutic modalities frequently requires development of relevant laboratory assays. This is especially true for the clinical uses of newly developed reagents such as murine monoclonal antibodies. We have described immunofluorescence, immunohistochemical, and enzyme‐linked immunosorbent assays (ELISA) for monitoring anticancer therapy with monoclonal antibodies. Immunofluorescence assays performed on single cell suspensions and immunohistochemical assays performed on freshly frozen biopsy tissue have confirmed tissue reactivity of the monoclonal antibody prior to infusion and have been used to measure in vivo antibody binding to target cells as well as antigenic modulation during therapy. An ELISA has been used to measure the serum concentrations of monoclonal antibodies; another ELISA has been used to detect the presence of human antibodies reactive with murine monoclonal antibody. These reproducible assays can be performed with commercially available reagents and provide an important data base for making clinical decisions concerning therapy with monoclonal antibodies.
Dry‐phase technology for immunoassays
Authors: Morris D. L. , Ledden D. J. , Boguslaski R. C.
Published: March 2007

Dry‐phase immunoassay technologies are reviewed. The systems described include the incorporation of homogeneous immunoassay technologies, such as SLFIA, ARIS, and enzyme‐channeling methods, into paper strips. Also described are the different approaches to integrating ELISA methods into multizoned reagent devices that allow convenient automated or manual assays.
Generation of region‐specific antibodies to modified proteins
Authors: Curtiss Linda K. , Steinbrecher Urs P. , Witztum Joseph L.
Published: March 2007

Nonenzymatic modifications of the ϵ‐ amine of lysine residues in proteins have been described in diabetes, uremia, high‐dose aspirin therapy, and alcoholism. In this review, we describe the generation of lysine‐modification‐specific antibodies that can be used to identify and to quantitate nonenzymatic glucosylation, carbamylation, acetylation, ethylation, or methylation of lysine residues. Polyvalent or monoclonal antibodies that are absolutely specific for the lysine‐specific modification are obtained by immunization with modified autologous or homologous low‐density plasma lipoproteins.
Chemosensitivity testing of small biopsy specimens
Authors: Kern David H. , Morgan Carol R.
Published: March 2007

Chemosensitivity testing has usually been limited to tumor specimens of 2–3 g or more. We evaluated the miniaturized, improved nucleic acid precursor incorporation assay (MINI‐assay) in 100 small biopsy specimens of 1 g or less. Tumor types included malignant melanomas; sarcomas; and breast, colon, lung, and ovarian carcinomas. Overall, 74/100 were evaluable. The evaluability rate was related to size: 41/48 (85%) 0.7–1.0‐g specimens were evaluable, as opposed to 22/35 (64%) 0.4–0.6‐g and 11/17 (64%) 0.1–0.3‐g specimens. Evaluability was not correlated with tumor types or whether the tumor was from a primary or metastatic site, but was related to yield of viable tumor cells. No viable tumor cells were obtained in 17 specimens, and thus no assay was performed. When 105 cells per well were plated, 49/54 (91%) assays were evaluable, but only 25/29 (86%) were successful when fewer cells were used. Four or more anticancer drugs could be tested in 69/74 (95%) of the evaluable assays. Yielding high evaluability rates and requiring fewer viable cells, the MINI‐assay has allowed us to perform chemosensitivity tests on previously unusable biopsy specimens.
Total triiodothyronine by fluorescence polarization immunoassay (FPIA)
Authors: Armbruster Dave , Harris Roderick , Scarbrough Rhonda , Tamez Carlos
Published: March 2007

A semiautomated fluorescence polarization immunoassay (FPIA) for total T3 performed using the TDx analyzer has been evaluated. Precision of the assay at a low level of T3 (<1.0 ng/mL) is not good with CVs of about 17% observed. Precision at moderate to high levels (1.7–5.6 ng/mL) is good (CVs = 11.3−4.1%). Low end imprecision is attributable to a lack of sensitivity, with a reliable detection limit of only about 0.9 ng/mL. An average recovery of added T3 of 96% was noted, and the assay is not affected by interference due to lipemia, bilirubinemia, or hemolysis. A methods comparison study of the FPIA test and total T3 by RIA yielded a regression equation of Y = 1.08 × −.28, r = 0.95. The TDx FPIA total T3 test is a quick, semiautomated procedure, offering the advantage of a stable, stored calibration curve. It is useful for quantitating elevated levels of total T3 as found in hyperthyroid conditions, and its performance is comparable to or better than RIA procedures for this purpose. However, it cannot be recommended for the evaluation of patients with T3 values below 1.0 ng/mL, and RIA tests are still preferable for this analytical range.
Toxicology screening patterns in hamilton county, ohio: Review of 1,710 comprehensive drug screens in five area hospitals
Authors: Merigian Kevin S. , Schroeder Timothy J. , Tasset Jerry J. , Pesce Amadeo J.
Published: March 2007

This retrospective study evaluated the results of comprehensive drug screens ordered in five local emergency departments; a university hospital, the Children's Hospital, the Veterans' Administration Hospital, and two community hospitals.

Four groups of drugs provided over 50% of positive screens–benzodiazepines, analgesics, opiates, and alcohols. Incidence of positive screens for analgesics, anticonvulsants, benzodiazepines, opiates, stimulants, and tricyclic antidepressant varied among the institutions. The university and Children's Hospitals ordered the largest number of patient visits in their emergency departments.

These results suggested that area hospitals have different toxicological patterns, and modifying comprehensive screens could be more cost‐effective on overdose patients. We retrospectively examined 60 screens which were ordered on patients at the University. We calculated an increased positive incidence and decreased cost per patient if screens were ordered on a “clinical panel” basis verses a total “comprehensive” basis. We conclude that clinical guidance will increase the incidence of positive screen results, be more cost‐effective, and provide useful information to the ordering physician.
Detection of human T‐Cell lymphotropic virus Type‐I provirus DNA by in vitro enzymatic amplification
Authors: Fujii Nobuyuki , Ogasawara Masanori , Ito Satoru , Tara Mitsutoshi
Published: March 2007

For the detection of the HTLV‐I provirus genomic DNA, we applied the polymerase‐chain‐reaction (PCR) dot‐blot assay system developed by Saiki et al. (14). DNA sequences coding the p24 in the gag region were chosen as targets to be amplified.

We checked genomic DNAs extracted from peripheral blood lymphocytes (PBL) of five adult T‐cell leukemia patients, one HTLV‐I‐associated myelopathy (HAM) patient, four asymptomatic carriers, and five normal individuals as negative controls. Although carriers sometimes showed low antibody titers in the particle‐agglutination test and revealed faint banding patterns in Western‐blot analysis, the PCR dot‐blot assay system can clearly detect the HTLV‐I provirus DNA. Furthermore, all data obtained with the specimens tested were confirmed by the PCR oligomer‐restriction (OR) procedure.

The PCR dot‐blot assay system is simple and rapid for the detection of the target DNA sequence, although it does not provide useful additional information, as does the Southern‐blot analysis. Therefore, it can be considered to be a powerful analytical system for the confirmation of HTLV‐I infections.
Serum Concentration of Chorionic Gonadotropin‐like Substance and Luteinizing Hormone in Children Measured by Sensitive Enzyme Immunoassay
Authors: Yano Koichi , Okuno Akimasa , Hashida Seiichi , Ishikawa Eiji
Published: March 2007

Serum levels of human chorionic gonadotropin (hCG)‐like substance and human luteinizing hormone (hLH) in healthy children aged 4–17 years were measured by sensitive enzyme immunoassay techniques. In enzyme immunoassay for hCG‐like substance, minimal cross‐reaction with hLH was observed. In enzyme immunoassay for hLH, there was a considerable cross‐reaction with hCG. However, serum levels of hCG‐like substance were below 0.08 IU/liter or less than one fourth of serum hLH levels. Therefore, values obtained for serum hLH levels were considered to be reliable. Serum levels of hCG‐like substance increased with increasing ages in some children, with the highest level 0.23 IU/liter in a male aged 14 years. Serum hLH levels were 0.02–0.7 IU/liter in children aged 4–8 years, elevated during the ages of 9 to 11 years, reaching the range of 3–27 IU/liter in children aged 12–17 years. The sensitive enzyme immunoassay technique used in this study will be useful for the detection of hypogonadotropic hypogonadism in children.