The DNA extruded by rat spleen cells in culture

1. Part of the DNA extruded by cultured rat spleen cells occurs in the form of a low density lipid complex. 2. The present work indicates that this complex is also associated with protein but not with RNA and its elementary properties have been studied. 3. For example, it is destroyed by freezing and thawing or by deoxycholate treatment and small quantities of copper salts added to the medium may either inhibit or stimulate its release depending on the conditions.     

Intra-arterial bolus of 125I labeled meglumine diatrizoate. Early extravascular distribution

A mixture of 125I labeled meglumine diatrizoate and 131I labeled human serum albumin was injected into the lower abdominal aorta of 30 anesthetized, laparotomized male rats. Measurements of the activities in cardiac blood and in different tissues of the hindlimbs and tests were perfomed at six time intervals ranging from 5 seconds to 2 minutes after injection, the determine early uptake and distribution volumes of diatrizoate. Concentrations and distribution volumes were initially much greater than values obtained after intravenous injection, but these differences had considerably decreased or disappeared by 2 minutes.     

Numerical and Experimental Performance Evaluation of the 3-Stage FROSTY Supercooled Cloud Collector

An evaluation of the collection characteristics of a new multistage cascade inertial impactor designed for size-resolved cloud drop collection has been performed. The FROSTY supercooled cloud collector is intended for the collection of supercooled cloud drops in a winter environment in three independent size fractions with stage 50% cut diameters of 15 θ m, 10 θ m, and 4 θ m. Two approaches were selected for the evaluation of the collector. Numerical simulations provided a visualization of the airflow patterns and drop trajectories through the collector while experimental laboratory calibration provided a quantitative analysis of true collection performance. For each of these methods, 50% cut diameters, efficiency curves, and wall losses for each stage of the collector were determined. Collection characteristics were determined experimentally by introducing fluorescein-tagged monodisperse drops into the collector and analyzing collection patterns by fluorescence. The experimental measurements at laboratory conditions indicated 50% cut diameters of 19.0, 11.5, and 5.0 θ m for the three stages. Adjusted for operation at collector design conditions, the 50% cut diameters were 17.0, 10.5, and 4.5 θ m. Numerical modeling of the airflow patterns and drop trajectories through the collector was performed with the commercially available Computational Fluid Dynamics (CFD) software package FLUENT. Trajectory simulations based on the average continuous phase (air) velocity field as well as trajectory simulations which included the effects of statistically derived turbulent velocity fluctuations on drop motion were performed. Comparisons between the numerical and experimental work indicated that the inclusion of turbulent fluctuation effects on drop motion provided much better agreement with experimental observations than trajectories based solely on average flow field velocities. However, the use of continuous phase velocity fluctuations also produced unrealistic losses to wall surfaces for small drop sizes. Despite this shortcoming, numerically derived 50% cut diameters and overall collection efficiency curve shapes for drop trajectories including turbulent velocity fluctuations agreed reasonably well with experimental observations.     

Unrelated donor bone marrow transplantation for chronic myelogenous leukemia: a decision analysis

BACKGROUND: Chronic myelogenous leukemia (CML) is an indolent but ultimately fatal disease. Because the natural history of CML varies and quality of life with CML may be excellent until shortly before death, deciding whether and when to pursue unrelated donor bone marrow transplantation is often difficult. OBJECTIVE: To compare early transplantation, delayed transplantation, and no transplantation for patients with chronic-phase CML on the basis of discounted, quality-adjusted life expectancy. DESIGN: A markov model comparing different strategies was constructed. This model considers patient age, quality of life, risk aversion, and the competing risks for CML progression and transplant toxicity. SETTING: Therapeutic decision at the time of diagnosis of CML. PATIENTS: The base case is a 35-year-old patient with intermediate-prognosis CML. Younger and older patients with better and worse prognoses are also evaluated. INTERVENTION: Early transplantation, delayed transplantation, and no transplantation. MEASUREMENTS: Quality-adjusted, discounted life expectancy. RESULTS: For patients with newly diagnosed CML, transplantation within the first year provides the greatest quality-adjusted expected survival, although this benefit decreases with increasing patient age. For a 35-year-old patient with intermediate-prognosis CML, transplantation within the first year results in 53 more discounted, quality-adjusted years of life expectancy than does no transplantation. This finding is robust even with varying baseline assumptions. CONCLUSIONS: These results support the use of early unrelated donor bone marrow transplantation for most patients with CML.