Effect of reticuloendothelial system stimulation on resistance to Rous sarcoma virus infection in chicks

By using a non-toxic reticuloendothelial system stimulant, lipid-Restim, derived from shark livers, we were able to demonstrate the following effects on growing Rous sarcoma tumors in young chicks. Prechallenge Restim treatment: Significant reduction of the percentage of chicks with tumors and prolongation of the latent period resulted from combined administration of Restim and specific antiserum. Postchallenge Restim treatment: The mortality data indicated that there was a significant increase in survival time and survival rate. Complete regressions

1 The term “regression” is used in this paper to mean complete macroscopical disappearance of the primary tumor at the site of inoculation of the virus.

occurred in a significant number of the Restim-treated chicks compared to the controls. Possible explanations of these findings are discussed.     

Coenzyme Q deficiency in mice following infection with Friend leukemia virus.

The specific activities of the succinate dehydrogenase-coenzyme Q reductase were assayed on mitochondrial preparations of this enzyme from spleen, liver, blood and peritoneal macrophages of mice infected with Friend leukemia virus, and of control mice. Significant increases in the deficiency of coenzyme Q-enzyme activity were found in the spleen and blood of infected animals as the infection progressed. No significant deficiency was observed in the liver or the peritoneal macrophages. The development of the deficiency and splenomegaly during infection seemingly correlate with previous data which showed that administration of coenzyme Q resulted in a reversal of splenomegaly and a reduction in mortality. A limiting factor in the resistance of mice to Friend leukemia virus appears to be the availability of coenzyme Q.     

Immunological senescence in mice and its reversal by coenzyme Q10.

A pronounced suppression of the humoral, hemolytic, primary immune response in old (22 months) mice was demonstrated as compared with this response in young (10 weeks) mice. The suppression is associated with a lower thymus weight:body weight ratio. In contrast, the ratios spleen weight:body weight and liver weight:body weight in 10 weeks and 22 months old mice remain almost constant. A single administration of coenzyme Q10--a non-toxic, non-specific stimulant of the host defense system--partly compensates the age-determined suppression of the humoral, immune response. This suppression probably results from an age-dependent imbalance of T cells: B cells ratio and a decline of their immunological responsiveness which is compensated by the administration of coenzyme Q10.     

An integrated system for the production of field shaping devices in radiotherapy

A system has been developed in our department that simplifies the production processes of field shaping devices in radiotherapy, integrating an image grabbing and processing facility at a radiotherapy simulator and an automated block cutter. The data acquisition subsystem captures images, processes and corrects them for pincushion distortions, creates a composite radiograph, records user defined contours of blocks and exports data to the block cutter controller. A robotic subsystem drives and controls the polystyrene cutting unit. The system has been experimentally evaluated. Errors in contour definition were found to be less than 1 mm for a broad range of gantry angles and not exceeding 1.5 mm for those gantry orientations that present maximum magnetic field related image intensifier distortion, while the automated block cutter is capable of cutting out contours in polystyrene with an accuracy comparable to that of commercially available systems. The system is expected to contribute to the overall improvement of radiotherapy processes, particularly in low budget radiotherapy departments, introducing improvements in accuracy and efficiency at minimum costs.     

Tissue redox activity as a sensing platform for imaging of cancer based on nitroxide redox cycle

The experience in free radical biology and medicine shows the crucial role of redox signalling in carcinogenesis. The cells and tissues of healthy mammals are characterised by a low level of reactive oxygen species (ROS) and some constant (reference) level of reducing equivalents. Increasing of ROS above the critical level provokes genomic instability. The present study describes universal methodology for direct imaging of tissue redox activity in carcinogenesis, which allows a differentiation of cancer development from normal condition. The experiments were conducted on: neuroblastoma-bearing mice; colon cancer-bearing mice; and healthy mice. The tissue redox activity was visualised in vivo by nitroxide-enhanced magnetic resonance imaging (MRI) on anesthetised animals. The method is based on nitroxide redox cycle, coupled with appearance/disappearance of MRI signal. The half-life (τ_1/2) of nitroxide-enhanced MRI signal in the respective tissue was used as a diagnostic marker. The study provides direct evidence that healthy and cancer-bearing mammalian tissues are characterised by different redox activities – a basis for cancer diagnosis. The tissues (cancer and ‘normal’) of cancer-bearing mammals were characterised by a long-lived MRI signal (τ_1/2 > 14 min), indicating a high oxidative activity. The tissues of healthy organism were characterised by a short-lived MRI signal (τ_1/2 = 1–3 min), indicating a high reducing activity. The study shows that tissue redox activity is a sensing platform for imaging of cancer using nitroxide-enhanced MRI. It also suggests that ‘normal’ tissues of cancer-bearing organism are susceptible to oxidative damage.     

Q-Pro: a quality control management system for medical equipment

Q-Pro is an application for quality control (QC) and inspection of medical equipment. The system has been designed on the basis of a broad requirements analysis, contributed by clinical engineers from several European countries and with a focus on current and forthcoming regulatory requirements concerning the quality control and risk management for medical equipment. Q-Pro comprises a generalized application, providing the necessary flexibility to accommodate the different degrees of difficulty and specialization in creating or customizing QC protocols, carrying out inspections and managing collected data. The system incorporates a tool library for QC protocol design, widely used multimedia as well as a local database for protocol and inventory data archiving. The paper presents a detailed account of the system context of use, design and functionality.