Elaboration of the preliminary Rheumatoid Arthritis Impact of Disease (RAID) score: a EULAR initiative.

BACKGROUND: Current response criteria in rheumatoid arthritis (RA) usually assess only three patient-reported outcomes (PROs): pain, functional disability and patient global assessment. Other important PROs such as fatigue are not included. OBJECTIVE: To elaborate a patient-derived composite response index for use in clinical trials in RA, the RA Impact of Disease (RAID) score. METHODS: Ten patients identified 17 domains or areas of health relevant for inclusion in the score, then 96 patients (10 per country in 10 European countries) ranked these domains in order of decreasing importance. The seven most important domains were selected. Instruments were chosen for each domain after extensive literature research of psychometric properties and expert opinion. The relative weight of each of the domains was obtained from 505 patients who were asked to "distribute 100 points" among the seven domains. The average ranks of importance of these domains were then computed. RESULTS: The RAID score includes seven domains with the following relative weights: pain (21%), functional disability (16%), fatigue (15%), emotional well-being (12%), sleep (12%), coping (12%) and physical well-being (12%). Weights were similar across countries and across patient and disease characteristics. Proposed instruments include the Health Assessment Questionnaire and numerical ratings scales. CONCLUSION: The preliminary RAID score is a patient-derived weighted score to assess the impact of RA. An ongoing study will allow the final choice of questionnaires and assessment of validity. This score can be used in clinical trials as a new composite index that captures information relevant to patients.

A model of adaptive visual processes of primary image processing.

A computer model of adaptive segmentation of two-dimensional visual objects was developed, based on neurophysiological and psychophysiological principles. The model imitates several stages of visual information processing. At the first stage, a preliminary assessment of the image is performed using a brightness pattern analyzer. At the second stage, control parameters are formed on the bases of the initial assessment. A defined control vector is synthesized for each type of starting image, which allows adaptive processing; this initiates two parallel mechanisms of primary image description: one contains the outlines of images and the sharp boundaries between their fragments, and the second contains areas of uniform intensity. The control parameter vector is applied to these two descriptions to analyze their brightnesses and spatial characteristics, and this is used as the basis for forming the regime for subsequent processing, which includes a set of processing operators whose parameters are tuned for each fragment of the image. The primary phasic and tonic descriptions are then used to extract individual fragments of the image (i.e., discrimination of figures from the background) and to form the final presentation. The resulting descriptions complement each other, creating a basis for quantitative measurements of image characteristics and allowing various signs needed for image classification to be formed. The computer program for adaptive image segmentation was tested using a large number of different two-dimensional half-tone objects, the purposes of these exercises including segmentation and measurement of objects in morphometric and cytometric studies.

[The effect of weak electromagnetic fields and ionizing radiation on the regeneration of the murine sciatic nerve]. / Vliianie slabykh élektromagnitnykh polei i ioniziruiushchei radiatsii na regeneratsiiu sedalishchnogo nerva myshei.

The influence of X-ray impulses (dose 0.003 cGy, longitudity 10 ns) and EM impulses (induction 0.003 mT) on sciatic nerve regeneration in mice after crush lesion was studied. Limb jerk amplitude at electric stimulation of nerve and postural reflex in thin rod in X + EM and EM groups were restored within 13th days after lesion, in control group within 15 days (p < 0.05). The beginning of repairing of postural reflex was early in X + EM group than on EM group, rehabilitation of limb jerk amplitude--in EM group. Histological examination demonstrated that myelin degenerated in EM group more rapidly as compared with X + EM and control groups. This data suppose different effects of EM and X + EM impulses on nerve-regenerating processes.

[Spontaneous synchronous discharges in hippocampal slices. Simulation and experiment]. / Spontannye sinkhronnye razriady v srezakh gippokampa. Modelirovanie i éksperiment.

Chaotic oscillations of extracellular potential of field-type nerve tissues are simulated by a 2D coupled map lattice. These tissues, say, the fields of the hippocampus, are represented by neural mass sheets consisting of current sources. The relationship between the source-sink ensembles and the extracellular field potential at each discrete instant of time t = 1, 2, ... is described by a single-site map creating chaos. The 2D coupled map lattice is viewed as a network of diffusively coupled the maps creating spatiotemporal chaos. The conversion of chaotic oscillations into synchronous ones, which are typical for epileptiform discharges, is studied. The results obtained are in good agreement with those derived from hippocampal slices treated with picrotoxin.

Paroxysmal activity in the rabbit visual cortex induced by photostimulation.

The combination of two epileptogenic factors--rhythmic photostimulation at frequencies of 5-6 Hz, and local injury to the visual cortex by freezing--were used to induce paroxysmal spike-and-wave type activity in rabbits. This activity (5-6 discharges per second) was observed near the injured site, as well as in the mirror foci, but it never extended to the frontal cortex. Spike-and-wave discharges were also observed in the lateral geniculate body and the superior colliculus. Diazepam completely inhibited this epileptic activity, but pentylenetetrazol and caffeine potentiated its manifestation. The dominant theta-rhythm frequency coincides with the main electroencephalogram synchronization frequency, and with the frequency of rhythmical photostimulation which was able to induce the seizures. These findings are discussed with respect to the theory of synchronization of biorhythms in the brain.

The effect of exposure to impulse X rays on normal and epileptic activity in rabbit brain.

Exposure to X rays (20 impulses of 4 Hz frequency, total dose 0.6-1.1 mGy) increased the epileptic activity of a focal area, which was produced in the visual cortex of rabbit brain by freezing with liquid nitrogen, and by stimulating with flashes of light at frequencies of 5-6 Hz. The number of seizure complexes during photostimulation for 5 s increased by 80% compared with the initial level, and this effect continued for 15 min. In control animals (with no epileptic foci), a decrease was observed in the main frequencies of the delta rhythm and the theta rhythm (by 90% and by 10%, respectively) over the cortex as a whole. In rabbits with experimental epilepsy, the delta rhythm decreased only in the frontal lobes and in the lateral geniculate body (by 30%), whereas the theta rhythm decreased only in the visual cortex (by 10%). Possible mechanisms for these effects are discussed.

[Reactions of mammalian nerve cells to small doses of radiation]. / Nekotorye osobennosti reaktsii nervnykh kletok mlekopitaiushchikh na malye dozy radiatsii.

In experiments with rat brain slices it was shown that a radiation-induced short-term increase in spontaneous neuron activity was mainly a function of dose rate. Pulsed X-radiation (pulse length of 2 X 10(-8) s, doses of 3 X 10(-5) to 6 X 10(-4) Gy) caused the most pronounced reactions that were almost completely prevented by caffeine, euphylline, and norepinephrine (10(-4) to 10(-3) M).

Effect of injection of RNA isolated from normal and epileptic cortexes of rabbits into functioning mollusc neurons.

Epileptogenic foci were formed in rabbit visual cortex by freezing with liquid nitrogen. RNA isolated from the epileptogenic cortex (RNAepl), or from the frontal lobes (RNAcont) was injected into spontaneously active neurons of the mollusc Planorbarius corneus. The amplitude and duration of the spontaneous action potentials generated following the injection of RNAepl were reproducibly higher than those produced following the introduction of RNAcont. But the time interval between injection and cessation of spontaneous activity was considerably shorter after RNAepl-injection than after RNAcont-injection. Perfusion of neurons with a solution containing puromycin substantially prolonged the period of spontaneous discharge generation in both cases. The addition of Co2+ to the perfusion solution restored the spontaneous rhythmic activity to cells in which the generation of spikes had ceased following the injection of RNAepl. The mechanism underlying these effects is discussed.

Coupled map lattice simulation of epileptogenesis in hippocampal slices.

Bioelectric activity of a nervous tissue and its synchronization with formatting epileptiform bursts are simulated by a coupled map lattice. The functional units of the map located in the lattice sites represent neural masses which consist of current sources and sinks. The sources lead to depolarization of neurons, and sinks provide hyperpolarization. The map describes a single variable--the bioelectric potential. This potential is created by the interplay of all current sources and sinks in the neural masses. The neural masses are diffusively coupled with each other both by electronic influence and synaptic coupling. Both mechanisms mentioned are suggested to be essential for the formation of synchronous bursts. The transition from chaotic activity to bursts was studied.

Response of hippocampal pacemaker-like neurons to low doses of ionizing radiation.

Spontaneous discharges of hippocampal pacemaker-like neurons are induced by X- and gamma-rays doses lower than 0.8 cGy. The effect is direct and connected with the activation of an endogenous mechanism of unit activity generation.

[The model of adaptive primary image processing]. / Model' adaptivnykh zritel'nykh protsessov pervichnoi obrabotki izobrazhenii.

A computer model of adaptive segmentation of the 2D visual objects was developed. Primary image descriptions are realised via spatial frequency filters and feature detectors performing as self-organised mechanisms. Simulation of the control processes related to attention, lateral, frequency-selective and cross-orientation inhibition, determines the adaptive image processing.

[Effect of small doses of roentgen radiation on the spontaneous impulse activity of the hippocampus in vitro]. / Deistvie malykh doz rentgenovskogo izlucheniia na spontannuiu impul'snuiu aktivnost' gippokampa in vitro.

X-Irradiation of rat hippocampus in vitro with low doses accelerated spontaneous impulse passage without concomitant changes in synaptic activity. There was a negative correlation between the original frequency of neuron discharges and the degree of quickening the impulses in response to the effect of radiation. Perfusion of slices by a noncalcium solution blocked the synaptic transmission but did not influence the response to the effect of ionizing radiation.