Mechanism of cryoprecipitation of anti-blood group B murine monoclonal antibodies

In our experience, some examples of mouse monoclonal antibodies of anti-B blood group specificity develop a precipitate when stored at 4 degrees C. This poses problems during the preparation of blood grouping reagents containing anti-B, and in the storage and use of such reagents. Here we show that this problem can be circumvented by alteration of the glycan moiety of the secreted immunoglobulin, either by glycosidase treatment of the partially purified immunoglobulin, or by the addition of glycan processing inhibitors to the hybridoma cell cultures. These findings have importance for the manufacture of monoclonal antibodies, and highlight a possible new role for carbohydrate in immunoglobulin interaction and immune complex formation.     

Primary pulmonary involvement of Fusarium solani in a lung transplant recipient

A case of cavitary lung disease caused by Fusarium solani in a lung transplant recipient is presented. A mechanism for development of this infection is proposed. Lipid complex amphotericin B (Abelcet) was effective in eradicating this infection. To our knowledge, invasive lung disease caused by the Fusarium species has not been previously reported in a solid organ transplant recipient.     

Influence of pH on the uptake of 5-fluorouracil into isolated tumour cells

To investigate the possible dependence of 5-fluorouracil (5FU) uptake in tumours on the intra- (pHi) and extracellular (pHe) pH, a pH gradient (deltapH) was imposed across the plasma membrane of ascites tumour cells in vitro, similar to that known to occur in some solid tumours in vivo, by incubation in media of PHe 5-8. A > or = 2:1 (intracellular/extracellular) accumulation of radiolabelled 5FU occurred after 5 min incubation of the cells with 0.5 mM 5FU at pHe of 5.0, 5.5 or 6.0. 5FU metabolism is slow under these conditions, and 5FU uptake was not affected by longer incubations up to 20 min, nor by the absence of a sodium gradient. pHi was estimated from the distribution of the weak acid, 5.5-dimethyl-2,4-oxazolidione ([14C]DMO) across the cell membrane. There was significant correlation between the intracellular/extracellular 5FU ratio and pHe (from pHe 6-8), deltapH and pHi (P < 0.02). Similar results were obtained with HT29 cells. Incubation with a drug that made plasma membranes permeable to H+ significantly decreased 5FU uptake in Lettre cells. The co-transport of 5FU may occur on a proton symport using the proton motive force of the deltapH.     

Introduction to building projection-based tiled display systems

This tutorial introduces the concepts and technologies needed to build projector-based display systems. Tiled displays offer scalability, high resolution, and large formats for various applications. Tiled displays are an emerging technology for constructing semi-immersive visualization environments capable of presenting high-resolution images from scientific simulation. The largest impact may well arise from using large-format tiled displays as one of possibly multiple displays in building information or active spaces that surround the user with diverse ways of interacting with data and multimedia information flows. These environments may prove the ultimate successor to the desktop metaphor for information technology work. Several fundamental technological problems must be addressed to make tiled displays practical. These include: the choice of screen materials and support structures; choice of projectors, projector supports, and optional fine positioners; techniques for integrating image tiles into a seamless whole; interface devices for interaction with applications; display generators and interfaces; and the display software environment     

Retardation of extinction of an escape response by prolonged, intense goal box shock.

Studied the effects of intense, response-contingent goal box shock on the extinction of a runway-escape response in 40 male albino rats by means of a 2?×?2 factorial design in which presence vs absence of goal box shock during escape training was crossed with the same factor during extinction. Of the 2 groups trained with shock in the goal box, the 1 shocked there during extinction exhibited dramatically enhanced resistance to extinction. The group not punished there extinguished more rapidly than any of the other 4 groups. The remaining 2 groups responded at levels between these 2 groups but did not differ from each other. Results are discussed in terms of various learning-theory mechanisms, such as conditioned fear and stimulus generalization, and with emphasis on similarities between the procedures of the present study and those extant "alley-shock" and "goal-shock" self-punitive designs. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of substantia nigra and caudate nucleus lesions on avoidance learning in rats.

Compared to 21 operated and 14 nonoperated controls, 36 male Sprague-Dawley albino rats with small bilateral lesions in the anteroventral caudate nucleus or the rostral substantia nigra were significantly impaired in the acquisition of 1-way active avoidance, passive avoidance requiring the inhibition of the previously acquired 1-way response, and shuttle-box avoidance. Ss with nigral lesions took significantly more trials to criterion than Ss with caudate lesions on 1-way avoidance. Results are considered in terms of the intimate anatomical and neurochemical relationships between these structures, and a circuit of structures involved in avoidance learning is suggested. (34 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

FACTORS GOVERNING SURFACE MORPHOLOGY OF SPRAY-DRIED AMORPHOUS SUBSTANCES

Changes in particle morphology (size, shape, and appearance) have been monitored during drying of drops of foods and food-related materials. The apparatus produces a single stream of drops of uniform size, using a vibrating-orifice device for drop production. The drop size and the time-temperature history of the drops as they fall can be varied and controlled.

Qualitative observations are reported for drying of aqueous solutions of lactose, maltodextrin, skim milk, and coffee extract, with different feed concentrations. Particular emphasis is placed upon the tendency for development of folds upon the particle surface. A mechanistic model is developed, relating the tendency for folding to the extent of viscous flow of surface material in response to a surface-energy driving force. This model gives semi-quantitative agreement with observations for solutes of different molecular weight (and hence different viscosity) and for different feed concentrations.     

Imaging of high-Z material for nuclear contraband detection with a minimal prototype of a muon tomography station based on GEM detectors

Muon Tomography based on the measurement of multiple scattering of atmospheric cosmic ray muons in matter is a promising technique for detecting heavily shielded high-Z radioactive materials (U, Pu) in cargo or vehicles. The technique uses the deflection of cosmic ray muons in matter to perform tomographic imaging of high-Z material inside a probed volume. A Muon Tomography Station (MTS) requires position-sensitive detectors with high spatial resolution for optimal tracking of incoming and outgoing cosmic ray muons. Micro Pattern Gaseous Detector (MPGD) technologies such as Gas Electron Multiplier (GEM) detectors are excellent candidates for this application. We have built and operated a minimal MTS prototype based on 30 cm×30 cm GEM detectors for probing targets with various Z values inside the MTS volume. We report the first successful detection and imaging of medium-Z and high-Z targets of small volumes (∼0.03 L) using GEM-based Muon Tomography.