An SVD Investigation of Modeling Scatter in Multiple Energy Windows for Improved SPECT Images.

In this work singular value decomposition (SVD) techniques are used to investigate how the use of low energy photons and multiple energy windows affects the noise properties of Tc-99m SPECT imaging. We have previously shown that, when modeling scatter in the projector and backprojector of iterative reconstruction algorithms, simultaneous reconstruction from multiple energy window data can result in very different noise characteristics. Further, the properties depend upon the width and number of energy windows used.

[Concept and interim result of the ALL-BFM 90 therapy study in treatment of acute lymphoblastic leukemia in children and adolescents: the significance of initial therapy response in blood and bone marrow].

In the ongoing trial ALL-BFM 90 for the treatment of childhood non-B cell acute lymphoblastic leukemia (ALL) 1468 unselected patients (pts) were enrolled from 84 centers in Germany and Switzerland from 4/90 to 12/93. Based on the results of the previous trial ALL/NHL-BFM 86 this treatment program focused especially on therapy modifications for average (MRG) and high risk (HRG) pts, on the evaluation of therapy response for prognosis, and on the identification of high risk pts by molecular genetics. For average risk pts consolidation therapy was intensified by the addition of L-asparaginase (L-ASP) on a randomized basis.

The importance and implementation of accurate 3D compensation methods for quantitative SPECT.

The purpose of this study was to investigate the importance of 2D versus 3D compensation methods in SPECT. The compensation methods included in the study addressed two important degrading factors, namely attenuating and collimator-detector response in SPET. They can be divided into two general categories.

Non-Hodgkin's lymphoma in four children infected with the human immunodeficiency virus. Association with Epstein-Barr Virus and treatment.

Background: Reports on lymphoid malignancy and its treatment in children infected with human immunodeficiency virus (HIV) are limited.

Methods: Antibodies to Epstein-Barr virus (EBV) were detected by indirect immunofluorescence. DNA was extracted from peripheral blood lymphocytes or biopsy specimens.

Quantitative single-photon emission computed tomography: basics and clinical considerations.

Although quantitative single-photon emission computed tomography (SPECT) has been the goal of much research effort for a number of years, only recently has it received wide interest, especially for clinical applications. It has been increasingly recognized that the achievement of quantitative SPECT will increase the accuracy of measurements, such as dimensions of specific regions of interest, absolute amount of radioactivity, and dosimetry calculations, and substantially reduce reconstruction image artifacts and distortions, thus, greatly improving clinical diagnosis. This article provides a review of the definition of terms, major factors affecting SPECT quantitation and their degrading effects on SPECT image quality, and methods to compensate for these effects.

Characterization of the leukotriene D4 receptor in dimethylsulphoxide-differentiated U937 cells: comparison with the leukotriene D4 receptor in human lung and guinea-pig lung.

The leukotriene D4 receptor has been fully characterized by radioligand binding in membrane preparations from dimethyl sulphoxide-differentiated U937 cells, a human monocyte leukemia cell line, and, in parallel experiments, compared with leukotriene D4 receptor found in human lung and guinea-pig lung preparations. [3H]Leukotriene D4 specific binding in differentiated U937 cell membranes is of high affinity (KD = 0.35 nM), saturable (Bmax = 287 fmol/mg protein), with differentiation resulting in a 3-5-fold increase in the number of detectable binding sites.

Simultaneous acquisition of emission and transmission data for improved thallium-201 cardiac SPECT imaging using a technetium-99m transmission source.

Transmission computed tomography (TCT) data provides useful complementary information to single-photon emission computed tomography (SPECT) reconstructions, especially for cardiac studies. In particular, TCT data has been used to correct for nonuniform attenuation in the chest. Typically the transmission data are acquired in a separate acquisition, but simultaneous acquisition is preferable both to save time and to avoid difficulties involved with registration.

Soluble CD14 participates in the response of cells to lipopolysaccharide.

CD14 is a 55-kD protein found both as a glycosylphosphatidyl inositol-linked protein on the surface of mononuclear phagocytes and as a soluble protein in the blood. CD14 on the cell membrane (mCD14) has been shown to serve as a receptor for complexes of lipopolysaccharide (LPS) with LPS binding protein, but a function for soluble CD14 (sCD14) has not been described. Here we show that sCD14 enables responses to LPS by cells that do not express CD14.

Haemophilus influenzae lipopolysaccharide disrupts confluent monolayers of bovine brain endothelial cells via a serum-dependent cytotoxic pathway.

An in vitro blood-brain barrier (BBB) model consisting of primary cultures of bovine brain microvascular endothelial cells was used to examine the effect of Haemophilus influenzae type b (Hib) on the BBB. Whole bacteria and purified lipopolysaccharide (LPS; greater than 10 ng/ml) caused marked cytotoxicity on the bovine brain endothelial cells. This effect could be completely blocked by polymyxin B.

Angiotensin II receptor recognized by DuP753 regulates two distinct guanine nucleotide-binding protein signaling pathways.

The 7315c cell, derived from a rat anterior pituitary tumor, expresses an angiotensin II (AII) receptor. [3H]AII binds to 7315c membranes specifically and saturably (Kd = 2.1 +/- 0.

Characterization of the leukotriene D4 receptor in hyperreactive rat lung.

A [3H]leukotriene D4 radioreceptor binding assay has been established in rat lung and has been used to fully characterize the leukotriene D4 receptor in lung membranes from an inbred strain of rats displaying non-specific bronchial hyperreactivity. [3H]leukotriene D4 specific binding in this tissue is of high affinity (KD 0.12 nM), saturable (Bmax 42 fmol/mg protein), inhibited by both guanine nucleotide analogues and sodium ions and increased by divalent cations.