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Biomedical subjects

S I Anisimov

Publications and source records attributed to S I Anisimov.

At least 19 recordsLinked to original sources
PubMed2001

Hydrodynamic waves in regions with smooth loss of convexity of isentropes: general phenomenological theory.

A general phenomenological theory of hydrodynamic waves in regions with smooth loss of convexity of isentropes is developed, based on the fact that for most media these regions in the p-V plane are anomalously small. Accordingly the waves are usually weak and can be described in the manner analogous to that for weak shock waves of compression. The corresponding generalized Burgers equation is derived and analyzed. The exact solution of the equation for steady shock waves of rarefaction is obtained and discussed.

Journal Article↗
PubMed1986

[Adhesion of the vitreous body to cured polymers].

The adhesive activity of several polymers as regard to vitreous body (VB) was examined by drying out the vitreous body on the surface of the materials under study. 3 types of polymers were compared with glass (silicon, polyurethan, polymethylmetacrilate). According to the reduction in adhesive activity as regard to VB the substances were ranged from silicon to glass. The authors believe that the mechanism of VB adhesion to polymers is linked to the absorption of gialuronic acid on their surface, which is part of VB. The above method is suggested for the selection of polymers used in the manufacturing of intraocular lenses.

Adhesiveness↗
PubMed1984

[Method of determining the colloidal status of the vitreous body].

A new method for the quantitative estimation of the vitreous body colloidal state has been suggested. For realization of the method a fragment of the vitreous body and an equal volume of water are dried out, and the drying time is registered. The higher is the ratio between the drying time of the vitreous body fragment and water, the higher is the density of the vitreous body gel. The drying out of the vitreous body fragment and water on the analytical balance cups permits the registration of the drying out process in the time course. Thus some additional parameters are obtained that characterize the object studied more completely. The method can be used in experimental and clinical investigations of the vitreous body and other biological liquids.

Animals↗
PubMedDate not supplied

[Unified classification of conditions united by the notion of "diffusive lamellar keratitis (D.L.K.)" in the corneal refractive surgery].

A total of 4810 laser keratomilase surgeries (LASIK) in myopia and hypermetropia were analyzed. The spherical equivalent of clinical refraction in myopia amounted to -6.56 +/- 1.34 diopters, in hypermetropia it amounted to +3.97 +/- 1.74 diopters. The refraction parameters in myopia ranged from 1.5 diopters to 12.0 diopters; in case of astigmatism they ranged from 0.5 diopters to 2.75 diopters, and in hypermetropia they varied from 1.5 to 6.25 diopters. The age of patients ranged from 18.5 to 52; there were 49.3% male patients and 50.7% female patients. The observation period was up to 2 years. The lamellar corneal incision was implemented by three types of microkeratomes: "Hansatome" (Germany), "Moria" (France) and "Nidek" (Japan). Photoablation was carried out by Keracor Techlas 217 (Germany) of the "flying dot" scanning type and by "Profil 500" (Russia). The primary DLK reaction of the dystrophic nature amounted, during the first year of using the method, to 1:75 cases, during the second year it was 1:350 cases. The share of secondary DLK manifestations ranged from 0.1 to 17% with regard for a type of complications. DLK can be characterized by various forms, phases and stages. The reaction can be primary (early) and secondary (delayed). Basically, it is a universal inflammatory response of keratocytes to a prolonged malfunction of lamellar flap due to disadaptation. It is described as a complication of the lamellar surgery as a whole and is, most probably, a response to the sutureless surgery. There are factors, which diminish the frequency of such complication. A new working classification of the DLK response is presented. A new clinical classification of DLK and DLK-like conditions in the corneal lamellar surgery is offered. Finally, notion "lamellar malfunction" is offered for a comprehensive usage in refraction surgery.

Adolescent↗
PubMedDate not supplied

[Photo-ablation of a corneal epithelium flap in complications after laser keratomileusis].

Three hundred and fifty-four LASIK surgeries made in myopia were analyzed. The share of epithelium-related complications made up 3.1%. Persistent irregular astigmatism and impaired visual acuity with correction shaped up in 5 cases. All patients underwent laser photoablation of the epithelium in the phototherapeutic keratectomy (PTK) regimen by using an original technique. The "Keracor 217 C" laser (2 mm spot, 120 mlJ./cm2 energy and 25 Hz frequency) was applied. The treatment resulted in a reliably improved visual acuity and normalized anterior corneal surface.

Adult↗
PubMedDate not supplied

[The results of hypophyseal irradiation with a proton beam in acromegaly patients].

The investigation of 26 acromegalic patients long after irradiation of the pituitary body with a proton beam showed clinical and hormonal improvement in 38% of the patients, clinical improvement without complete growth hormone normalization in 46%, and the absence of any effect in 15%. The latter was mainly a result of partial irradiation of pituitary adenoma. Some patients after proton irradiation demonstrated signs of adenohypophyseal functional insufficiency, more marked in patients with a decreased level of Gy (over 5 ng/ml). A conclusion is that proton beam therapy is effective (provided all criteria for patients' eligibility are observed) and can be used as an independent method for the treatment of acromegalic patients.

Acromegaly↗
PubMedDate not supplied

[Computed tomography in the Multidisciplinary Science and Technology Complex "Eye Microsurgery"].

The paper is devoted to analysis of the results of CT in 1000 patients examined in the Multibranch Research and Technology Complex "Eye Microsurgery". The specific feature of CT in this institution is that 52% of all investigations of ophthalmological patients fall to the share of eyeball abnormality and 40%--to a study of the other parts of the organ of vision. CT indications are extended for low tension glaucoma, complicated high myopia, and for monitoring the position of microsurgical implants. The use of CT in such a highly specialized medical institution as the MRTC "Eye Microsurgery" is considered indispensable.

Eye Diseases↗
PubMedDate not supplied

[Correlations between clinico-functional and computerized tomography parameters in patients with optic atrophy of diverse etiology].

Comprehensive examinations of the optic nerve anatomy and function in atrophies of various origins have revealed a correlation between computerized tomography data and clinical and functional characteristics in 67 patients. A staged pattern of the development of anatomic shifts corresponding to CT data on the changes in the optic nerve diameter and density in accord with the length of the disease has been determined, as well as a relationship between these shifts and the patients' age and the degree of the calcification of the internal carotid arterial walls. CT signs of the optic nerve atrophy are related to functional disorders. Impaired circulation in the internal carotid arteries augments the atrophic process in the optic nerve. These data may be useful for the selection of a method for the management of optic nerve atrophy and for assessment of the treatment efficacy.

Electrophysiology↗
PubMedDate not supplied

[Computed tomography with variable levels of energy of x-ray radiation].

Method of computer tomography with variable radiant energy is described. It permits to compensate the distortions in computer-tomographic sections in case of change in tube operating conditions and in visualization of information about tissue composition within the sectional limits. The developed method increases the efficacy of computer tomography.

Humans↗
PubMedDate not supplied

[Computerized tomography of the orbit and optic nerve canals in optic nerve atrophy of diverse etiology].

Computerized tomography has been used to examine 10 patients with cranial injuries aftereffects presenting as optic nerve atrophies (Group 1), 24 patients with nontraumatic optic nerve atrophies (Group 2), and 89 subjects without optic nerve abnormalities. Density asymmetry in the projection of the optic nerve canal cranial openings has been the computerized tomography sign that indicated the involvement of the optic nerve in Group 1 patients. Increased pneumatization of the main bone sinus has been detected 2 times more frequently in Group 2 patients.

Adolescent↗
PubMedDate not supplied

[Radiation dose to patients and informativeness of the images obtained during eye examinations using x-ray computed tomography].

Reducing the scanning time and the X-ray tube anode current to 80-100 mA is the main way of reducing the radiation dose without noticeably lowering the tomogram image quality in examination of the eye area using the USA QUAD-1 X-ray computer tomograph of the fourth generation. The optimum tube voltage is 140 kW. Narrowing the collimator slit and reducing the number of sections can also lower the total radiation dose, but these measures are less universal for they are determined by clinical situation.

Eye↗