Childhood all blasts retain phenotypic and genotypic characteristics upon long-term serial passage in NOD/SCID mice.

For children with an early bone marrow relapse or relapsed T-cell acute lymphoblastic leukemia (ALL), allogeneic bone marrow transplantation (BMT) is currently the only therapeutic option with a curative approach. Here, the graft versus leukemia (GvL) effect seems to play an important role for long-term immunological control of leukemia. If a bone marrow donor is not available, autologous stem cell transplantation after high-dose chemotherapy has been used as an alternative option. The objective of this work was the induction of tumor specific cytotoxic T-lymphocytes (CTL) against autologous leukemic cells in order to generate the missing GvL effect after autoBMT. The first step was the establishment of an optimized and reliable mouse model. The second step was the induction of a GvL effect in an allogeneic approach to serve as a basis for further GvL experiments in an autologous approach in this mouse model. Leukemic cells from 11 out of 16 different pediatric patients were successfully established in mice and in one case passaged over 19 generations without changes of genotype or phenotype. The antileukemic activity of allogeneic human MNC as a GvL reaction and an accompanying GvHD in the mouse model was shown. Xenotransplanted ALL can be considered a clinically relevant model mimicking the human conditions and as a useful preclinical tool for the evaluation of novel immuno- or genetherapeutic approaches.

The impact of variable tint optics (Transitions Gray) on vision-related quality of life in normal volunteers: a randomized clinical comparison in a warm climate.

PURPOSE: A randomized crossover comparison of Transitions Gray variable tint optics (VTO) vs clear and fixed-tint lenses was undertaken to evaluate the impact of VTO on vision-related quality of life (VRQOL) in a warm climate. METHODS: Fifty-nine patients were randomized to one of four lens crossover groups: Transitions-->clear; clear-->Transitions; Transitions-->fixed-tint; fixed-tint-->Transitions. Each lens was worn for 30 days. VRQOL was measured using a newly developed and validated questionnaire instrument-the Transitions VRQOL. Changes in visual acuity were assessed by functional exam. RESULTS: Overall, Transitions was associated with the greatest improvement in VRQOL relative to clear and fixed-tint lenses without compromise in acuity. Transitions proved statistically superior to clear lenses, most notably in vision comfort both indoors and outdoors. Seventy percent of all patients selected Transitions as their primary lens at the end of the study. CONCLUSIONS: Transitions brand VTO offer patients significant and clinically meaningful improvements in VRQOL superior to clear lenses. VRQOL assessments provide clinicians with valuable information above and beyond visual acuity to help optimize lens product selection and enhance patient satisfaction.

[Functional magnetic resonance imaging (MRI) of hepatic ischemia in the rabbit. Contribution of a particulated contrast agent (AMI-25)]. / Imagerie par résonance magnétique (IRM) fonctionnelle de l'ischémie hépatique chez le lapin. Contribution d'un agent de contraste particulaire (AMI-25).

A functional approach of the rabbit portal ischemia was performed on five New Zealand rabbits using magnetic-resonance (MR) imaging and an MR-specific contrast agent for the liver. The hepatic vascularization and the functionality of the phagocytosis cells were both studied with a single low dose of a unique contrast agent-superparamagnetic iron oxide particles (SPIOs). After a rapid i.v. injection of SPIOs, functional vessels and normally perfused liver parenchyma appeared with positive signal enhancement, whereas the ischemic area remained dark (cold spot). After the intravascular time period, the well-known negative enhancement induced by these particles on normal parenchyma was observed, with the difference of the ischemic liver, and could be related to the uptake of SPIOs by functional Kupffer cells.

Noninvasive assessment of no-reflow phenomenon in a canine model of reperfused infarction by contrast-enhanced magnetic resonance imaging.

The aim of this study was to test whether contrast-enhanced magnetic resonance (MR) imaging may assess in vivo the severity of the no-reflow phenomenon in a dog model of infarction with 2-hour coronary occlusion followed by reperfusion (6 hours). Subsecond MR imaging combined with intravenous bolus administration of superparamagnetic iron oxide particles (SPIO) was performed at the fifth hour of reperfusion. An MR index was calculated using the difference of signal-intensity enhancement between ischemic and nonischemic zones during the SPIO first pass. Dogs were separated into two groups according to the severity of ischemia: collateral blood flow in the central ischemic zone at 120 minutes of occlusion (radioactive microsphere technique) < 22.5% of the flow in the nonischemic zone (group I) or > 22.5% (group II). Mean collateral blood flow during occlusion was lower in group I (11.3% +/- 2.9%, n = 7) than in group II (66.8% +/- 19.8%, n = 6, p < 0.05). Mean infarct size was significantly larger in group I (58.6% +/- 4.9% of the area-at-risk, n = 7) than in group II (16.5% +/- 6.5%, n = 6, p < 0.05). For the entire population (n = 13), the infarct size was inversely correlated to the collateral blood flow (r = -0.64, p = 0.02, standard error of estimate = 0.24). The relative rate of enhancement in ischemic myocardium (MR index) was significantly lower in group I (38.1% +/- 10.9%) than in group II (142.8% +/- 32%; p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Dynamic contrast-enhanced MR angiography of pulmonary embolism: comparison with pulmonary angiography.

OBJECTIVE: Subsecond contrast-enhanced MR angiography, which is not a flow-based technique and does not require cardiac gating or breath-holding, provides multiplanar, rapid, dynamic visualization of the pulmonary arteries. Accordingly, we evaluated the use of this technique in the diagnosis of thrombi in both the proximal and peripheral portions of the pulmonary arteries. Digital subtraction angiography was used as the gold standard for the diagnosis. SUBJECTS AND METHODS: Twenty-three consecutive patients with suspected pulmonary embolism were included in the study. All patients had intraarterial digital subtraction angiography, which showed emboli in 12 patients (13 proximal and six peripheral emboli). MR angiography was done within 24 hr of digital subtraction angiography. Subsecond contrast-enhanced MR angiograms were obtained in the long axis of each pulmonary artery after a unique injection of contrast medium (0.1 mmol/kg) in an antecubital vein. Fifteen dynamic frames of each pulmonary artery were alternately obtained in less than 1 min. MR angiograms were interpreted by two observers who had no knowledge of the findings on digital subtraction angiography. A diagnosis of pulmonary emboli was made when MR angiograms showed a constant intraluminal filling defect or an abrupt vascular cutoff. RESULTS: All thrombi in the proximal branches of the pulmonary arteries were visualized on MR angiograms (n = 13), whereas none of the thrombi in the distal part of the pulmonary arteries were seen (n = 6). In the 11 patients in whom no pulmonary emboli were shown by digital subtraction angiography, findings on MR angiograms were normal (sensitivity, 0.7; specificity, 1.0). CONCLUSION: Our results suggest that dynamic contrast-enhanced MR angiography is an accurate method for detecting emboli in the proximal portions of the pulmonary arteries but is of no value in detecting peripheral emboli.

Automated myocardial edge detection from breath-hold cine-MR images: evaluation of left ventricular volumes and mass.

This paper describes an automated edge detection method for the delineation of the endo- and epicardial borders of the left ventricle from magnetic resonance (MR) images. The feasibility of this technique was demonstrated by processing temporal series of cardiac MR images obtained in 12 healthy subjects and acquired from the apex to the base of the heart in multiple anatomic short axis planes with a breath-hold cine-MR acquisition sequence. This procedure allows the entire heart to be imaged in less than 5 min. The automatic program correctly identified the edges in most cases. In poor contrasted images, a fast and user-friendly interactive procedure was used to correct the border delineation. The proposed method for the contour tracing requires a limited degree of control by the user and thus considerably reduces the tedious and long operator time inherent in the usual manual contour tracing tool. The left ventricular volumes were directly measured from these sets of contours by using the Simpson rule, allowing the end-diastolic volumes (EDV), the end-systolic volumes (ESV), the ejection fraction (EF) and the myocardial mass to be determined. The values measured in this study with the dedicated software were similar to the literature values (EDV = 78.3 ml/m2; ESV = 21.1 ml/m2; EF = 73%). Associated with the ultrafast breath-hold cine-MR imaging, the described edge detection method provides an efficient clinical tool for the direct assessment of cardiac function.