[Peculiarities of CI processor fitting in children with auditory neuropathy spectrum disorders]. / Osobennosti nastroiki protsessora kokhlearnogo implantata u detei so slukhovoi (auditornoi) neiropatiei.

The peculiarities of cochlear implant (CI) processor fitting in children with auditory neuropathy spectrum disorders (ANSD) were investigated. At the 1-st fitting of the CI processor a standard protocol of parameters was used in all patients, including patients with cochlear nerve hypoplasia. After the initial fitting session, the behavioral tonal thresholds with CI in 55% of patients were 30-35 dB, in 32.% of patients - 40-50 dB. After 3-6 months, 65% of children with ANSD showed significant progress in auditory-speech development, which made it possible to use the standard protocol of tuning parameters for them with the most comfortable and threshold levels of electrical stimulation adjusted according to the child's reactions. The best dynamics was observed in 2 children with presynaptic ANSD with a confirmed DFNB9 (OTOF) gene mutation. In 35% of children, there was no progress in distinguishing speech signals and instability of reactions to sounds persisted after 6 months using of CI and speech therapy training, despite the low tonal thresholds of hearing. In these children the coding strategy was changed, the stimulation frequency was reduced, and the pulse width was increased. This helped to improve the discrimination of sounds with CI and progress in the child's speech development. The results demonstrate that children with ANSD require more frequent correction of CI processor settings: 1st year - every 3 months, then at least 2 times a year until the optimal coding strategy and settings are achieved. To predict the effectiveness of CI and determine the optimal tactics for setting up the CI processor in patients with ANSD, the preoperative examination should include MRI of the cerebellopontine angle to detect anomalies of the cochlear nerve and genetic examination to identify mutations that cause hearing impairment in patients with ANSD.

[Psychoacoustic tests for perceptual assessment of processor fitting in patients with cochlear implants]. / Ispol'zovanie psikhoakusticheskikh testov dlya pertseptivnoi otsenki nastroiki protsessora kokhlearnogo implanta u glukhikh patsientov.

THE AIM OF THE STUDY: Was to study the possibility of using a battery of psychoacoustic tests to assess the tuning of the cochlear implant processor (CI) in deaf patients. METHODOLOGY: The study involved 60 prellingually deaf patients aged 10 to 23 years with oral speech skills. To assess the quality of the CI processor tuning, in addition to traditional methods, a special battery of psychoacoustic tests was used. The first block of tests assessed the perception of the basic characteristics of sound signals (duration, temporal structure, spectrum, timbre) and was used to assess the initial setting. The second block of tests, intended for patients with experience using CI, included tasks to distinguish acoustically similar and dynamically changing signals, etc. RESULTS: At the end of the initial CI setup session, patients with short signal perception problems were identified. Adjusting the frequency of electrical stimulation in patients has increased their ability to distinguish between sounds. During the second tuning session of the CI processor, 6 months later, a group of patients with difficulties in perceiving acoustic information in the low-frequency range was identified - distinguishing melodic intervals, changing the pitch of sounds, highlighting the voice of the target speaker. The «problem¼ patients underwent additional correction of the CI processor setting and the corresponding auditory training, which improved the test performance and subjective perception of sounds. CONCLUSION: The use of psychoacoustic tests expands the possibilities of fine tuning the CI processor, taking into account the individual characteristics of the patient's auditory perception at different stages of CI use, especially in «problem¼ patients.

[Sequential bilateral cochlear implantation with long interval between surgeries in deaf-blind patient]. / Posledovatel'naia bilateral'naia kokhlearnaia implantatsiia s dlitel'nym intervalom mezhdu operatsiiami u slepoglukhogo patsienta.

The efficacy of sequential bilateral cochlear implantation with long interval between surgeries (18 years) was investigated in deaf-blind patient (22 years old man, lost hearing and vision after meningitis at the age 2.5 years). At the age 4 years he got cochlear implant at right ear. His speech skills completely disappeared before the implantation. Auditory-speech rehabilitation with cochlear implant was successful - patient has good auditory, language, speech, cognitive skills. At the age 22 years patient made decision to get cochlear implant at the left ear after breakdown of internal part of cochlear implant at right ear in spite of successful reoperation. After activation of new processor (all electrodes were activated) the patient got daily auditory training with cochlear implant at left ear (Concerto/Opus 2, Medel) on the base of 'auditory' method, in daily life patient uses 2 devices. After 1 month of using cochlear implant at left ear the patient recognized environmental sounds and music instruments, words and sentences in close set tests EARS battery, the score for OLSA test in quiet was 90%, but the perception in noise was complicated. The balance of parameters of fitting for 1-st and 2-nd processors and special auditory training with two cochlear implants provided the development of initial binaural interaction. Perilinqually deaf patients can achieve high effect after sequential bilateral cochlear implantation with long interval between surgeries. The necessary conditions are - preservation of electrical activity of auditory nerve, intensive structured auditory training with new 'ear', patient's motivation of using of cochlear implant at 'new' ear.

[Organization of remote long-term support of the patients with cochlear implants in distant regions].

The concept of remote long-term support of the patients with cochlear implants is suggested to cope with the problem of the increasingly growing number of patients with cochlear pathology. The authors deem it necessary to provide intraoperative support and postoperative follow-up technologies for the patients living far from the cochlear implantation centres. A scheme for the remote selection of patients and their intraoperative monitoring is proposed with the use of implant telemetry, electrical stapedial reflex (eSRT) testing, auditory response telemetry (ART), and surgical on-line counseling. Remote follow-up and rehabilitation should include cochlear implant tuning, speech therapy, and on-line workshops for the patients and/or specialists. The choice and the use of software and hardware for this purpose are discussed. The concept of remote long-term support turned out to be an efficacious, reliable, time-saving, and cost-effective tool for providing high-tech medical aid to patients with ENT diseases in the Krasnoyarsk kray (territory).

[Effect of elastic properties of the crab axon sheath on the movement of nerve fibers at the action potential]. / Vliianie uprugikh svoistv obolochki aksona kraba na dvizhenie nervnogo volokna pri potentsiale deistviia.

The shear modulus (nu) of single giant axon of the crab Carcinus maenas was determined by measuring the axon elastic stretching up to 1-10%. The value obtained for nu (5-7 X 10(3) dn X cm) is more than that for sheaths of reptilian and mammalian red blood cells by 10(4)-10(6) times. Proteolysis of the axon sheath by pronase solution (2 mg/ml, 15-20 min) increases the amplitude of axon movement at the action potential by 8-10 times. It is suggested that the collagen fibers, Schwann's and connective cells are passive structures of the axon sheath, and that potential-depend axon movement at the action potential is due to deformation of the axolemma and submembrane layer.

[Effect of calcium ions on sorption of phthalocyanin dye by membranes of individual nerve fibers]. / Vliianie ionov kal'tsiia na sorbtsiiu ftalotsianinovogo krasitelia membranami odinochnykh nervnykh volokon

The binding of vital anionic phthalocyanine dye Heliogen blue K (HBK) by crab axons has been studied cytophotometrically. HBK koes not penetrate the cell but stains membranes selectively. The removal of Ca-ions from the surrounding artificial sea water (a.s.w.) leads to an obvious desorption of an ion-bound fraction of HBK from the fibre, provided the removal of Ca-ions from a.s.w. is combinded with slight hypotonia or with addition of EDTA. The hypotonia, which has no effect on sorption, causes swelling of fibres facilitating the removal of Ca-ions from membrane, i.e. the effect similar to that of EDTA. In the Ca-ions devoid hypotonic solution, the decrease of sorbed dye makes up 1.4% per minute of the initial concentration, and in the hypotonic solution with EDTA - this decrease reaches 0.95%. It is suggested that the withdrawal of Ca-ions from the membrane results in conformational changes of the membrane protein component. These changes are expressed as redistribution of changes, detected with the aid of the HBK anion.

[Heterogeneity and heat resistance of esterases of the pancreas and liver of rats]. / Geterogennost' i teploustoichivost' esteraz podzheludochnoi zhelezy i pecheni krys

A higher heat resistance of loosely-attached microsomal esterases as compared with that of free esterases of the rat's pancreas is due to a higher proportion of heat resistant slow carboxylesterases in the former. More significant differences in the heat resistance of pancreas and liver is caused not only by different heterogeneity of esterases, but also by their qualitative differences.

[The suppression of rapid local surface oscillations in human erythrocytes slows and weakens their adhesion to glass]. / Podavlenie bystrykh lokal'nykh kolebanii poverkhnosti éritrotsitov cheloveka zamedliaet i oslabliaet ikh prikreplenie k steklu.

Rapid local oscillations of the erythrocyte surface with amplitude 200-300 nm are decreased by 10 times following addition of wheat germ agglutinin (10(-77) M). In this case the rate of erythrocyte adhesion to the cover glass is delayed approximately by 3-9 times. The total suppression of erythrocyte surface oscillations occurs in hypo-osmic solution or in a 0.01% solution of glutaraldehyde. It coincides with a two-fold decrease of erythrocyte adhesivity to the glass. It is suggested that the rapid erythrocyte surface oscillations may control the rate of cell adhesion to the substrate.

[Destructive changes in the outer perimembrane layers (glycocalyx) of Zajdela ascites hepatoma cells under the action of UV radiation]. / Destruktivnye izmeneniia vneshnikh primembrannykh sloev (gliko-kaliksa) kletok astsitnoi gepatomy Zaidela pri deistvii UF izlucheniia.

Immediately after far (254) nm and near (300--380 nm) UV light in small and moderate doses alcian blue sorption by glycocalix of Zaidela ascitic hepatoma cells decrease, which is indicative of destruction and solubilization. The effect of UV light on the cell surface is compared with the action of trypsin. Contribution of the damage of outer perimembrane layers to the lethal effect of UV light is discussed.

["Spontaneous" oscillations of the cell surface in the frequency interval of 0.2-30 Hz]. / "Spontannye" kolebaniia kletochnoi poverkhnosti v chastotnom interval 0.2--30 Gts.

The local transverse displacements of the cell surface within the frequency range of 0.2-30 Hz occur on animal cells attached to cover glass: fibroblasts 3T6, primary culture of rat cardiomyocytes, mouse lymphocytes, human macrophages and erythrocytes, frog erythrocytes. The area of the cell rim, moving transversely, is no more than 0.5 X 0.5 microns. The maximum amplitude of the local transverse surface displacement is different in various cell types, being maximum (350-400 nm) in human erythrocytes and minimum in fibroblasts 3T6, mouse lymphocytes and human macrophages (20-30 nm). High-amplitude oscillations of human erythrocytes and low-amplitude oscillations of frog erythrocytes correlate with differences in the size of elastic shear modulus.

[Spectrophotometric study of the surface of human erythrocytes and their ghosts by using a phthalocyanine dye]. / Spektrofotometricheskoe issledovanie poverkhnosti éritrotsi ov cheloveka i ikh tenei s pomoshch'iu ftalotsianinovogo krasitelia.

Human intact erythrocytes and their ghosts (resealed and unresealed) were stained by the vital dye Heliogen Blue, which does not penetrate the cell being only sorbed by its membrane. The absorption spectra of the sorbed dye were examined. On the external surface of the membrane, the molecular (monomer) state of dye sorption is revealed, whereas on the interior side the dye sorption is mostly in the polymolecular (dimer) state. The differences in staining can be evaluated by the monomer-dimer ratio (M/D), which may be used for comparison between the sorption characteristics of membrane preparations.

[Form of red and white human erythrocyte ghosts and the ultrastructure of the internal perimembrane layer]. / forma krasnykh i belykh tenei éritrotsitov cheloveka i ul'trastruktura vnutrennego primembrannogo sloia.

The shape of red and white ghosts and the ultrastructure of the inner perimembrane layers have been studied. The cytoplasmic perimembrane layer is proved to have a fibrous lattice-like structure. The ghosts with a great amount of hemoglobin have ellipsoid or deformed circular shapes. White, hemoglobin-free ghosts have an irregular shape. After their resealing with a following incubation in an isoosmostic (300 imomole) succarose solution they assume a shape of narrow arcous profiles containing fibrous lattice-like material. The organization of this material is variable and depends on the degree of ghost hydration. It is proposed that this spectrin-like material may account for the stability of the long-range membrane organization.

[Changes in the form and ultrastructure of white erythrocyte ghosts during sealing and phthalocyanine dye sorption]. / Izmenenie formy i ul'trastruktury belykh éritrotsitarnykh tenei pri ikh zamykanii i pri sorbtsii ftalotsianinovogo krasitelia.

A study was made of the shape and ultrastructure of human erythrocytes unsealed and resealed for sucrose. The unsealed white ghosts assume unregular ameboid-like shapes. After resealing they acquire more regular spherical forms; the sub-membrane layer is dissociated, the plasma membrane undergoes numerous deformations. The same ultrastructure is revealed for the ghosts obtained from erythrocytes stained with phthalocyanine anionic dye (Heliogen Blue SBL). This dye is bound to the outer surface of the red blood cell, occupying no more than 2-4% of the cell surface.

[Loosely bound proteins and membrane ultrastructure of erythrocyte ghosts]. / Slabosviazannye belki i ul'trastruktura membran tenei éritrotsitov

The loosely bound erythrocyte ghost proteins, extracted by distilled water, 5 mM EDTA, tris-HCI buffer at pH 8.5, veronal-acetate buffer at pH 8.5 and by a 1.5% solution of acetic acid, were studied electrophoretically using a polyacrilamid gel with 0.1% sodium docecyl sulphate. 20% proteins with m.v.12 000-120 000 polypeptid chains were released from ghosts transferred from phosphate buffer to distilled water. 5 mM EDTA extracts, in addition, a m. w. 215000 protein. The increase of the negative change brought about the extraction of proteins of the molecular weight equal to 12 000-250 000. After extraction of 12% or more loosely bound proteins the reduction of membrane-attached materials was seen with the electron microscope. Shifts of pH from 6.3 to 7.4 and the treatment with 5mM EDTA resulted in reduction of the premembrane material, ghosts sticking together after the latter procedure.

[Rapid local oscillations of the surface of the human erythrocyte]. / Bystrye lokal'nye kolebaniia poverkhnosti éritrotsita cheloveka.

The transverse displacements of the human erythrocyte surface with amplitude 300-400 nm in the frequency range 0.2-30 Hz are recorded on the minimal area erythrocyte rim (approximately 0.5 X 0.5 microns). These local oscillations of the surface are diminished at hypoosmotic erythrocyte swelling, on addition of substances which increase the membrane rigidity (0.01% glutaraldehyde, 0.5 mM 4-hydroxymercuribenzoate, cell membrane stain--0.002% Heliogen Blue) and on discocyte--echinocyte transformation due to addition of 1-2 mM 2,4-dinitrophenol. The amplitude of transverse displacements is reduced by 1.7-2 times on erythrocytes of patients with inherent microspherocytosis. These erythrocytes have inherent defects in spectrin. It is suggested that spectrin is important for rapid local oscillations of the human erythrocyte surface.

[Analysis of nerve fiber deformation during excitation]. / K analizu deformatsii nervnogo volokna pri vozbuzhdenii.

A description of the potential--dependent strains of the nerve fiber is considered as a problem of finding the velocity and pressure distributions in two liquid volumes which are divided by a thin cylindric shell. The isotropic shell equations were used as the boundary conditions for this problem. The strain amplitude predicted is near to the observed one, but the strain dynamics in the model discussed does not coincide with the one recorded under the experimental conditions.