[Non-Invasive Methods for the Control of Human Spinal Locomotory Systems].

We studied the interrelations between the activation of the receptors of musculoskeletal system and the spinal cord stimulation in the regulation of locomotor behavior in healthy subjects. We observed the effect of afferent stimulation on the patterns of stepping movements caused by percutaneous stimulation of spinal cord. It was found that the combination of percutaneous spinal cord stimulation and vibrostimulation increases the amplitude of leg movements. It was shown that the vibrostimulation of limb muscles at a frequency of less than 30 Hz may be used for comtrolling involuntary movements, caused by non-invasive stimulation of the spinal cord.

[Effects of locomotor training and functional electrical stimulation on postural function in children with severe cerebral palsy].

Cerebral palsy (CP) considerably impairs the ability to maintain upright stance. In the present study the effects of locomotor training and functional electrical stimulation (FES) on postural control have been determined in children (n = 27) aged 6­12 years with severe CP. The severity level of the CP clinical manifestations was determined as 3 according to the Gross Motor Function Classification System (GMFCS) classification. All patients participated in 15 half-hour sessions of mechanic therapy using robot-assisted passive stepping. In 12 out of 27 children, the locomotion therapy was accompanied with FES. Stabilometry and plantography tests were performed before and after the course of interventions. In addition, similar posturographics tests were performed in 23 healthy children same age. Postural control in children with CP was characterized by a forward shift of the center of pressure (COP) projection; higher values of the COP trajectory area and length, as weel as by mean amplitude of the COP oscillations, and the absence of COP response to the eyes closed condition. After treatment, the posturographic characteristics had a tendency to normalization in relation to the values obtained in neurologically intact children. The improvement was observed in 43% of children without FES and in 75% of children which used FES. Analysis of plantograms revealed normalization of footprints in children received FES. Thus, it was demonstrated that FES combined with locomotor training resulted in the improvement in vertical posture control in children with severe CP.

[Transcutaneous electrical stimulation of the spinal cord: non-invasive tool for activation of locomotor circuitry in human].

A new tool for locomotor circuitry activation in the non-injured human by transcutaneous electrical spinal cord stimulation (tSCS) has been described. We show that continuous tSCS over T11-T12 vertebrae at 5-40 Hz induced involuntary locomotor-like stepping movements in subjects with their legs in a gravity-independent position. The increase of frequency of tSCS from 5 to 30 Hz augmented the amplitude of evoked stepping movements. The duration of cycle period did not depend on frequency of tSCS. During tSCS the hip, knee and ankle joints were involved in the stepping performance. It has been suggested that tSCS activates the locomotor circuitry through the dorsal roots. It appears that tSCS can be used as a non-invasive method in rehabilitation of spinal pathology.

[Optimal rehabilitation of patients with coronary heart disease in outpatient setting].

The problem of invalid rehabilitation in Russia is an important state task and dictates necessity of design of an effective state program of primary prevention of cardiovascular diseases. Common global practice of medico-social model is based on complex detailed medico-social aid. Rehabilitation of postmyocardial infarction patients consists of three phases (stages): hospital posthospital (readaptation) and postreconvalescent (supportive). The program includes physical, psychological and pharmacological rehabilitation. Departments of readaptation and medico-social rehabilitation provide effective conduction of all kinds of rehabilitation. The Moscow North-East Regional Administration has a rich experience in organization of departments of readaptation and medico-social rehabilitation. The departments practice an individual approach to the patients and work in a close contact with bureaus of medico-social commission of experts. Management of patients by cardiologist, rehabilitation specialist and outpatient clinic's physicians provides uninterrupted staged rehabilitation, timely correction of pharmacotherapy, early patient referral to invasive investigations and treatment of coronary heart disease. A course of rehabilitative measures lasts 2 months. Setting up departments of medico-social rehabilitation in outpatient clinics provides more effective use of money assigned by the state for social support of invalids.

[Analysis of locomotor activity in decerebrated cats during electromagnetic and epidural electrical spinal cord stimulation].

It was shown that the epidural and the electromagnetic tonic stimulation with frequency 5 Hz applied to the lumbal as well as to the cervical region of the spinal cord enabled stepping on a moving treadmill belt in decerebrated cats. It was found that there were differences in initiation of the stepping movements during epidural and electromagnetic stimulation depending on the region of spinal cord stimulation. Stimulation at frequency of 0.3 Hz induced single reflex responses in the anterior and posterior limbs. On the basis of analysis of the response structure it was concluded that the locomotor ability during epidural and electromagnetic stimulation depended on the degree of polysynaptic pathways activation. The hypothesis about stepping pattern generator activation through the dorsal roots during epidural stimulation and more direct activation of neuronal locomotor networks in the case of electromagnetic spinal cord stimulation is discussed.

[Role of a local therapeutic service in the timely identification, treatment, and rehabilitation of patients with coronary heart disease].

Local polyclinic therapists' long experience in timely identifying, treating and rehabilitating patients with coronary heart disease (CHD) is analyzed. A local therapist's attention is given to diferent course types--the clinical manifestations of CHD. The principles of continuity in the work of a therapist and a hospital: possibilities of extrahospital treatment are denoted; indications for hospitalization are specified. Rehabilitative measures include psychotherapy sessions in addition to drug, dietary, and exercise therapies. Continuity in the work of a therapeutic unit and a sociomedical expert commission contributes to the elaboration of clearer criteria for determining the degree of working capacity loss.

[Initiation of locomotion in decerebrated cat by using of impulse magnetic field projected onto the spinal cord segments].

The motor effects induced by impulse magnetic field (IMF) applied to lumbar as well as to cervical enlargements in decerebrated cat were studied. The magnetic coil with diameter 8 cm was placed on the distance 1-2 cm over the spinal cord. Single magnetic spinal cord stimulation with intensity 0.5-1 Tesla as well as continuous magnetic stimulation with frequency of 1 Hz and intensity 0.5 Tesla was performed. Single magnetic stimulation of lumbar enlargement elicited reflex responses in proximal and distal hind limb muscles. Continuous stimulation induced the locomotor activity in hind limbs on moving treadmill belt by activation of neuronal spinal locomotor networks (generator of stepping movements). The stimulation of lumbar enlargement involved into the locomotor activity only hind limbs. Continuous magnetic stimulation of cervical enlargerment evoked coordinated stepping movements in fore- and hind limbs. Initially stepping movements raised in hind limbs and then in forelimbs. After cessation of magnetic stimulation some coordinated stepping movements were observed. Thus, for the first time we showed a possibility to induce the locomotor activity in decerebrated cat by magnetic stimulation. The obtained results demonstrate the ability of non-invasive mode of neuronal spinal locomotor network activation. This approach opens new perspectives for using magnetic stimulation in clinical practice.

The role of cutaneous afferents in controlling locomotion evoked by epidural stimulation of the spinal cord in decerebrate cats.

The effects of the cutaneous input on the formation of the locomotor pattern in conditions of epidural stimulation of the spinal cord in decerebrate cats were studied. Locomotor activity was induced by rhythmic stimulation of the dorsal surface of spinal cord segments L4-L5 at a frequency of 3-5 Hz. Electromyograms (EMG) recorded from the antagonist muscles quadriceps, semitendinosus, tibialis anterior, and gastrocnemius lateralis were recorded, along with the kinematics of stepping movements during locomotion on a moving treadmill and reflex responses to single stimuli. Changes in the pattern of reactions observed before and after exclusion of cutaneous receptors (infiltration of lidocaine solution at the base of the paw or irrigation of the paw pads with chlorothane solution) were assessed. This treatment led to impairment of the locomotor cycle: the paw was placed with the rear surface downward and was dragged along in the swing phase, and the duration of the stance phase decreased. Exclusion of cutaneous afferents suppressed the polysynaptic activity of the extensor muscles and the distal flexor muscle of the ipsilateral hindlimb during locomotion evoked by epidural stimulation of the spinal cord. The effects of exclusion of cutaneous afferents on the monosynaptic component of the EMG response were insignificant.

[The role of skin afferent in regulation of locomotion evoked by electrical epidural stimulation of spinal cord in decerebrated cats].

The role of hindpaw skin afferent input in the locomotor pattern formation induced by epidural spinal cord stimulation was investigated in decerebrated cats. Locomotor activity was evoked by continuous 3-5Hz stimulation of dorsal surface of L4-L5 spinal segments. Kinematic and electromyographic activity (EMG) of m. Quadriceps, m. Semitendinosus, m. Tibialis anterior an m. Gastrocnemius lateralis before and after blocking of skin receptors in one hind limb were recorded. In addition, reflex responses in the hind limb muscles to epidural stimulation with frequency 0.5 Hz were analysed. Blocking of skin receptors of the foot with chlorothane paw irrigation or 2 % lidocaine administrated into the hind paw was performed. After blocking of skin receptors of the foot the stepping pattern changed. Stepping with dorsal foot placement and dragging during swing phase was observed. Duration of stance phase significantly decreased. Inhibition of polysynaptic activity of proximal and distal extensor muscles and distal flexor muscles of hind paw during locomotion was found. Monosynaptic responses after blocking of skin receptors of the foot changed insignificantly.

[Mathematical modeling of the mechanisms of locomotory pattern formation under epidural spinal cord stimulation with consideration of peripheral feedback].

The mechanisms of nervous regulation of locomotory activity of the spinal cord and participation of afferent peripheral feedback from lower limb muscles in the formation of locomotory patterns were investigated. The set of electromyograms of lower-limb muscle groups recorded in experiments on mesencephalic cats with application of electric epidural stimulations of lumbar segments of the spinal cord is described by a nonlinear dynamic model constructed on the basis of the Van-der-Pol equation with the compelling member. The conditions of occurrence of the regime of self-oscillations were investigated depending on the parameters of external influence. A modified equation was proposed, which takes into account the role of the afferent feedback and delay between the beginning of stimulation and muscle reaction. The conformity of the mathematical model with experimental data was shown, which makes possible its use both for the description of the mechanism of locomotory pattern formation under epidural spinal cord stimulation and the choice of optimum stimulation conditions.

Formation of locomotor patterns in decerebrate cats in conditions of epidural stimulation of the spinal cord.

Acute experiments on decerebrate cats were performed to study the mechanism of formation of the locomotor pattern in conditions of epidural stimulation of the spinal cord. These studies showed that only segments L3-L5 contributed to generating the stepping pattern in the hindlimbs. At the optimum frequency (5-10 Hz) of stimulation of these segments, formation of electromyographic burst activity in the flexor muscles was mainly due to polysynaptic reflex responses with latencies of 80-110 msec. In the extensor muscles, this process involved the interaction of a monosynaptic reflex and polysynaptic activity. In epidural stimulation, the stepping pattern was specified by spinal structures, while peripheral feedback had modulatory influences.

[Features of stepping pattern formation in decerebrated cats under epidural spinal cord stimulation]. / Osobennosti formirovaniia lokomotornykh patternov u detserebrirovannoi koshki pri épidural'noi stimuliatsii spinnogo mozga.

The mechanisms of stepping pattern formation initiated by epidural spinal cord stimulation in decerebrated cats, were investigated. It is shown that the ability to produce the stepping pattern involve the L3-L5 segments. In flexor muscle, the formation of stepping pattern under optimal stimulation frequency (5-10 Hz) of these segments is provided by polysynaptic activity with the latency 80-110 ms. In extensor muscle, this process is realized through interaction of monosynaptic reflex and polysynaptic activity. The stepping pattern under epidural stimulation is determined by spinal structures with modulation influence of the peripheral feedback.

Bioelectric activity of spinal cord in patients with vertebrospinal pathologies.

A method for functional evaluation of spinal cord conducting systems in patients with vertebrospinal diseases is proposed. The method is based on the analysis of changes in electrospinoneurogram recorded with epidural electrodes below the injury during an attempt at voluntary activation of foot muscles. The degree of changes in electrospinoneurogram frequency during voluntary command addressed to motoneurons of the lumbar enlargement reflect the state of descending spinal systems.

[Biological characteristics of coagulase-negative staphylococci isolated from conjunctivitis]. / Biologicheskaia kharakteristika koagulazonegativnykh stafilokokkov, vydelennykh pri kon"iunktivitakh.

The biological properties of 101 strains of coagulase-negative staphylococci isolated from conjunctival secretions of conjunctivitis patients, as well as from healthy persons were studied. More than a half of these strains (66%) were identified as Staph. epidermidis. 18% of the strains differed from this species only by the absence of phosphatase activity. The existence of the phosphatase-negative variants of Staph. epidermidis was inferred from this fact. About 1/3 of the cultures could not be identified in accordance with the scheme of the International Subcommittee on the Taxonomy of Staphylococci and Micrococci. The biological activity of the cultures isolated from conjunctivitis patients did not differ from that of the cultures isolated from healthy persons. The frequent occurrence of hemolytic activity in the strains isolated from both conjunctivitis patients and healthy persons was noted (88% and 83%, respectively). The conclusion on the variegated character and lability of the phenotypic characteristics of staphylococci has been made.

[Significance of determining novobiocin sensitivity in the taxonomy of staphylococci]. / Znachenie opredeleniia chuvstvitel'nosti k novobiotsinu v taksonomii stafilokokkov.

Novobiocin sensitivity of 96 strains belonging to various staphylococcal species was studied. It was noted that Staph. saprophyticus significantly differed from Staph. aureus and Staph. epidermidis with respect to the above antibiotic. The MIC up to 2 micrograms/ml and the growth inhibition zones of 26--35 mm in diameter were characteristic of Staph. aureau and Staph. epidermidis, while the respective figures for most of the strains of Staph. saprophyticus were 32--64 micrograms/ml and 12--17 mm. However, 28 percent of the strains of Staph. saprophyticus did not differ with respect to their movobiocin sensitivity from the other 2 species. It is concluded that the "novobiocin test" may be used for differentiation of staphylococci, within the genera. At the same time it was shown that the method of the paper sensitivity discs compares very favourably with the method of serial dilutions in agar not only because of its simplicity and convenience of manipulation with single strains, but also of the possibility of identifying the population heterogenicity with respect to novobiocin sensitivity.

[Importance of carbohydrate tests for interspecies differentiation of staphylococci]. / Znachenie uglevodnykh testov dlia mezhvidovoi differentsiatsii stafilokokkov.

The authors present the results of interspecies identification of coagulaso-negative staphylococci isolated from different sources. Modification of the method of aerobic carbohydrate and alcohols fermentation of hard media is described. Use of the latest recommendations of the International Subcommittee on taxonomy of staphylocossi and micrococci permitted to identify the greater part of 120 strains studied as Staph. epidermidis and Staph. saprophyticus; however, 1/3 of the cultures differed from these species ("intermediate" strains). Galactose and mannose fermentation was characteristic of Staph. epidermidis, and the absence of fermentation of these carbohydrates--of Staph. saprophyticus. The differences in the fermentation of mannite and tregalose, on the one hand, and on mannose and galactose--on the other, were characteristic of 57% of the "intermediate" strains. The data obtained permitted to draw a conclusion on nonhomogeneity of the group of coagulase-negative staphylococci by their reference to different carbohydrates and alcohols, and on a possibility of existence of not only of different species of these staphylococci, but also of their biochemical variants.