Iodine-131-anti-B1 radioimmunotherapy for B-cell lymphoma

PURPOSE: The CD20 B-lymphocyte surface antigen expressed by B-cell lymphomas is an attractive target for radioimmunotherapy, treatment using radiolabeled antibodies. We conducted a phase I dose-escalation trial to assess the toxicity, tumor targeting, and efficacy of nonmyeloablative doses of an anti-CD20 monoclonal antibody (anti-B1) labeled with iodine-131 (131I) in 34 patients with B-cell lymphoma who had failed chemotherapy. PATIENTS AND METHODS: Patients were first given tracelabeled doses of 131I-labeled anti-B1 (15 to 20 mg, 5 mCi) to assess radiolabeled antibody biodistribution, and then a radioimmunotherapeutic dose (15 to 20 mg) labeled with a quantity of 131I that would deliver a specified centigray dose of whole-body radiation predicted by the tracer dose. Whole-body radiation doses were escalated from 25 to 85 cGy in sequential groups of patients in 10-cGy increments. To evaluate if radiolabeled antibody biodistribution could be optimized, initial patients were given one or two additional tracer doses on successive weeks, each dose preceded by an infusion of 135 mg of unlabeled anti-B1 one week and 685 mg the next. The unlabeled antibody dose resulting in the most optimal tracer biodistribution was also given before the radioimmunotherapeutic dose. Later patients were given a single tracer dose and radioimmunotherapeutic dose preceded by infusion of 685 mg of unlabeled anti-B1. RESULTS: Treatment was well tolerated. Hematologic toxicity was dose-limiting, and 75 cGy was established as the maximally tolerated whole-body radiation dose. Twenty-eight patients received radioimmunotherapeutic doses of 34 to 161 mCi, resulting in complete remission in 14 patients and a partial response in eight. All 13 patients with low-grade lymphoma responded, and 10 achieved a complete remission. Six of eight patients with transformed lymphoma responded. Thirteen of 19 patients whose disease was resistant to their last course of chemotherapy and all patients with chemotherapy-sensitive disease responded. The median duration of complete remission exceeds 16.5 months. Six patients remain in complete remission 16 to 31 months after treatment. CONCLUSION: Nonmyeloablative radioimmunotherapy with 131I-anti-B1 is associated with a high rate of durable remissions in patients with B-cell lymphoma refractory to chemotherapy.     

Risk factors of arteriosclerosis in patients with severe bradycardia arrhythmias]

The frequency and distribution of risk factors of arteriosclerosis were determined in 405 patients with implanted cardiac pacemakers and compared with the corresponding results of patients with cardiac infarction. The most frequent risk factors were smoking (43,5%), hypertension (35,2%), and diabetes (34,3%) in males, hypertension (52,3%) and diabetes (49,7%) in females. The frequency of cardiac infarction was in average 19,5%. In the infarction group diabetes was lower in both sexes (23,5% and 35,8%), respectively), hyperlipoproteinemia and smoking were more frequent. From the different distribution of risk factors it is suggested, that coronary arteriosclerosis is not the most important etiologic factor in the development of bradycardic dysrhythmias. The higher percentage of diabetes in the pacemaker group could point to metabolic disturbances or specific diabetic vascular disease as harmful factors to the conduction system.     

Stimulus and response contingencies in the misbehavior of rats.

Misbehavior by rats was produced in Exps I (16 Wistar female albino rats) and II (15 Sprague-Dawley female albino rats) by pairing a ball bearing with food or by requiring contact with the ball bearing for food (Exps IV, 6 Ss, and V, 11 Ss). Misbehavior occurred before and after eating the food pellet. The frequency, complexity, and duration of prepellet misbehavior was increased by delay of food until after the ball bearing exited (or was programmed to exit) and by requiring contact with the bearing to obtain food. Alternative goal-directed behaviors occurred in Pavlovian contingencies in which food was delivered before the bearing was programmed to exit. Postpellet misbehavior tended to occur when food was delivered before the bearing was programmed to exit and before S released the bearing. Omission of food delivery on contact reduced the duration, complexity, and frequency of misbehavior, although experienced Ss continued to contact (Exp III, 15 Ss). Misbehavior was affected by both stimulus- and response-reward contingencies but showed characteristic organization and topography under both types of contingency. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiple-fluorophore-specie detection with a tapered Fabry-Perot fluorescence spectrometer

A novel fluorescence spectrometer and method for the simultaneous detection of multiple-fluorophore species in a no-moving-parts, instantaneous manner is described. In the reported embodiment of the instrument, a tapered Fabry-Perot filter is used to spatially encode the fluorescence spectrum from a multiple-dye-containing test sample. Using a pseudoinverse reconstruction algorithm, we spectrally decode the particle concentration for each dye specie in the test sample. Experimental results are reported along with a theoretical treatment of the method.     

Expanding the concept of simulator fidelity: the use of technology and collaborative activities in training maritime officers

The theoretical contribution of this paper lies in introducing the concept of social fidelity to bridge the gap between computer technology and collaborative learning activities in simulator-based training. The concept has usually been limited to the technological aspects of simulator training with an assumption that a high level of fidelity equals a high physical resemblance between a simulator and the real work environment. The objective of this article is to expand the prevailing understanding of the concept of simulator fidelity and explore social factors that may influence perceived training quality among professional maritime officers. This qualitative study aims to broaden the scope from technological aspects to an emphasis on task and collaborative factors. The empirical material used is based on observations of two different simulator programs for professional maritime officers and focused interviews with bridge officers participating in the sampled training. The research aims to deepen the knowledge on how learning unfolds in a simulator-based training context characterised by extensive use of advanced computer technology and collaborative activities. The research demonstrates how trainer–trainee interactions, task factors and simulator technology may influence perceived level of fidelity and training quality. The article is concluded by offering a set of recommendations for future design of maritime simulator-based training.     

Viscoelastic effects in nanometer‐scale contacts under shear

We demonstrate the effects of shear modulation on the viscoelastic response of nanometer‐scale single‐asperity contacts under static and dynamic loading conditions. Contact stiffness and relaxation time are determined for contacts to poly(vinylethylene) using a scanning force microscope (SFM). Knowledge of the torsional stiffness κ_Θ of the SFM cantilever is not required to determine the relaxation time. The relaxation time was several orders of magnitude slower than the bulk relaxation time but decreased slowly to the bulk value as the sample age increased. Contacts showed no evidence of microslip. We show that the shear response observed during the making and breaking of the contacts provides information about the time evolution of the contact area that is not available in force vs. distance curve measurements. This revised version was published online in June 2006 with corrections to the Cover Date.     

Direct ink writing of ceramic matrix composite structures

We present the development of an ink containing chopped fibers that is suitable for direct ink writing (DIW), enabling to obtain ceramic matrix composite (CMC) structures with complex shape. We take advantage of the unique formability opportunities provided by the use of a preceramic polymer as both polymeric binder and ceramic source. Inks suitable for the extrusion of fine filaments (<1 mm diameter) and containing a relatively high amount of fibers (>30 vol% for a nozzle diameter of 840 μm) were formulated. Despite some optimization of ink rheology still being needed, complex CMC structures with porosity of ~75% and compressive strength of ~4 MPa were successfully printed. The process is of particular interest for its ability to orient the fibers in the extrusion direction due to the shear stresses generated at the nozzle tip. This phenomenon was observed in the production of polymer matrix composites, but it is here employed for the first time for the production of ceramic matrix ones. The possibility to align high aspect ratio fillers using DIW opens the path to layer‐by‐layer design for optimizing the mechanical and microstructural properties within a printed object, and could potentially be extended to other types of fillers.