Correlation between LC50 for Adult Fish and Fish Embryos.

Testing for substance toxicity for living organisms is an important step in the development and adaptation of new drugs for various purposes. Analysis of the dependences between toxicological parameters of chemical substances for various test objects and physicochemical properties of these agents is a promising trend. Partition coefficient logP (logKow) was chosen as the key physicochemical parameter determining the toxicological parameters of the same substance for hydrobionts at different developmental stages. We found a correlation between decimal logarithm of the ratio of LCe50 for fish embryos to LCa50 for adult fish and logP. This dependence was found as a liner combination of equations obtained by drawing a trend line between experimental points and calculation of Pearson's correlation coefficient R.

[Protective action of fish muscle extracts against cellular senescence induced by oxidative stress]. / Zashchitnoe deistvie ékstraktov iz myshts ryb ot indutsirovannogo okislitel'nym stressom kletochnogo stareniia.

Muscle extracts of some fish species, i.e. pike (Esox lucius), sterlet (Acipenser ruthenus), pink salmon (Oncorhynchus gorbuscha) and, to a lesser extent, perch (Perca fluviatilis) and Russian sturgeon, (Acipenser gueldenstaedtii) prevent the development of premature senescence of the human embryonic fibroblasts induced by the sublethal concentration of H2O2. Muscle extracts of other fish species tested, i.e. coho salmon (Oncorhynchus kisutch) and zander (Sander lucioperca), have not demonstrated this feature. Cell proliferation increased after the action of the senescence-inhibiting muscle extracts. Possible mechanisms of the action of nature biologically active compounds that interfere with the development of stress-induced cell senescence are discussed.

Dependence between LD50 for Rodents and LC50 for Adult Fish and Fish Embryos.

We revealed empirical dependences between common logarithm of a ratio of rat oral LD50 to LCa50 for adult fish and lgP for 50 different chemicals; and common logarithm of a ratio of the oral LD50 in rodents to LCe50 for fish embryos and lgP for 30 different chemicals. The dependences were obtained by constructing a trend line between experimental points and calculation of Pearson's R correlation coefficient as a measure of regression significance. These dependences can show the influence of substance lipophilicity on its toxicity for aquatic organisms comparing to mammals.

X-ray absorption near-edge structure anomalous behaviour in structures with buried layers containing silicon nanocrystals.

Substructure and phase composition of silicon suboxide films containing silicon nanocrystals and implanted with carbon have been investigated by means of the X-ray absorption near-edge structure technique with the use of synchrotron radiation. It is shown that formation of silicon nanocrystals in the films' depth (more than 60 nm) and their following transformation into silicon carbide nanocrystals leads to abnormal behaviour of the X-ray absorption spectra in the elementary silicon absorption-edge energy region (100-104 eV) or in the silicon oxide absorption-edge energy region (104-110 eV). This abnormal behaviour is connected to X-ray elastic backscattering on silicon or silicon carbide nanocrystals located in the silicon oxide films depth.

[On motivations of adolescents to promote a healthy lifestyle].

There was studied the motivation of modern adolescents to promote healthy lifestyle. There were observed two arrays, including adolescent-schoolchildren aged 16-17 and 13-14 years in Moscow. The results showed that health occupied one of the first places among the positive motivations, being stable dominant in the period of 13-17 years. The real motivation for a healthy lifestyle coincides with the perspective and informed choice coincides with the life goals. In this, almost all of the identified negative motivation are "manageable", available to be modified or eliminated.

[Capacities of angiography in the imaging of abnormal changes in the cerebral arteries].

The study was based on the angiographic examination of 233 patients with prior subarachnoidal hemorrhage. Angiographic study was performed using the Seldinger technique by contrasting both carotid and vertebral arteries. Twenty-three patients in whom arterial aneurysm had been detected by digital subtraction angiography underwent 3D angiography. The authors improved a procedure during which a contrast agent was manually injected into the internal carotid or vertebral artery, by using a 20-ml disposal syringe with controlled maximum developed pressure and flow increase rate up to 2.0 ml/sec for 4-5 sec during rotary scanning and the administration of the radiocontrast medium was stopped when an image appeared on the monitor at 190 degrees (190.0, 200.0) C-arm rotation. This procedure could decrease significantly the volume of the administered contrast agent from 18 to 8 (8.0, 10.0) ml and reduce the time of radiation exposure from 6 to 4 (4.0, 5.0) sec. The improved angiographic modes for the right vertebral and right carotid artery could visualize pathological changes in these arteries and establish a relationship, namely: due to degenerative dystrophic processes of the cervical spine there is a tendency for higher pathological changes in the vertebral arteries with an increased stage of osteochondrosis in the cervical spine (R = 0.95; p = 0.014).

[Current issues in x-ray diagnosis of cervical osteochondrosis in the course of medical rehabilitation].

The results of studying 500 patients with neurological manifestations of cervical osteochondrosis are presented. All the patients underwent in the vertical position X-ray studies in the frontal, lateral, and axial projections, as well as functional spondylography. The development of radiological signs in patients with cervical osteochondrosis and that of the morphological and functional signs of degenerative and dystrophic changes in the cervical spine are discussed. Comprehensive evaluation of osteochondrosis used criteria for cervical motor disorders and impaired disk amortizing and spinal fixing functions. The degree of intradural space compression was also estimated. The studies have yielded a new classification of osteochondrosis and recommendations at the stages of medical rehabilitation.

[X-ray colonometry in the diagnosis of colonic dyskinesias and inflammatory diseases].

Clinical and X-ray studies were made in 316 patients, which revealed intestinal dyskinesia, chronic colitis, and nonspecific ulcerative colitis in 105, 133, and 78 patients, respectively. Irrigoscopy (administration of a contrast enema, examination of the mucosal contour, and double contrasting) was performed in all the patients, by analyzing X-ray planimetric indices. X-ray colonoplanimetry makes it possible to objectify the interpretation of the X-ray pattern in chronic inflammatory diseases of the large bowel and colonic dyskinesia.

[Computer analysis of the contours of the large intestine for the purpose of disease diagnosis]. / Komp'iuternyi analiz konturov tolstoi kishki s tsel'iu avtomaticheskoi diagnostiki zabolevanii.

The authors put forward a new method of structural analysis of images, based on an automatic search for regularities of signs of colonic diseases in the shape of contours of colonic segments. The regularities obtained were used as diagnostic signs. The results of analysis of the shape of contours of the 1st (cecum and the ascending colon) segment and the 5th (the rectum) segment in 83 patients. The results of CT diagnosis coincided with verified clinical conclusions.

[Effect of autolysis on the physico-chemical properties of mammalian skin]. / Vliianie autoliza na fiziko-khimicheskie svoistva kozhnogo pokrova mlekopitaiushchikh.

Alterations in physico-chemical properties and in content of several biochemical components were found in skin during postmortal storage of the tissue at the temperature 22 degrees and 5 degrees and relative moisture 92%. Within 96-120 hrs of the postmortal storage a decrease in content of hydrate-bound water and of glycosaminoglycans occurred in the tissue. The alterations were accompanied by an increase in temperature of hydrothermic denaturation and in module of elasticity of the skin. As a result of autolysis solubility of collagen in water was increased at 65 degrees and its acid soluble fractions tended to become denatured although the content of hydroxyproline was unaltered. The processes occurring in the skin within the first period after death, might be considered as a two-step sequence: formation of additional interstructural hydrogen bonds and structure transformation of both collagen and glycosaminoglycans due to the effect of proteinases.

[Two possible mechanisms for forming supramolecular structures of the collagen type]. / Dva vozmozhnykh mekhanizma obrazovaniia nadmolekuliarnykh struktur kollagenovogo tipa.

Comparative electron microscopic investigation of submolecular structure formation of native collagen molecules and denaturated collagen peptides in tropocollagen and gelatin gels was carried out. Submolecular terminal structures were similar. Fibrils exist with cross striation region of 64--70 nm. In spite of this the intermediate steps in the formation of both structures differ. In case of collagen the bundle of parallel microfibrils forms the thick fibrils. In case of gelatin the aggregates of spherical anisotropic particles form the fibrils of gelatin gels.

[Psychophysiological correlations in paroxysmal forms of cardiac rhythm disorders]. / Psikhofiziologicheskie sootnosheniia pri paroksizmal'nykh formakh narushenii serdechnogo ritma.

Fifty-two patients with paroxysmal disorders of cardiac rhythm were under observation for periods of 6 months to 3 years. Paroxysmal supraventricular tachycardia was registered in 16, ventricular tachycardia in one, paroxysmal cardiac fibrillation in 35. The method of comprehensive examination of personality (modified MMPI test, Cattell's and Hekhausen's tests) made it possible to reveal certain characteristic features of the personality and the actual psychic condition of all patients. Treatment with modern psychotropic agents (predominantly tranquilizers) improved the course of arrhythmia considerably in most patients; a tendency to normalization of the psychic condition was noted simultaneously. The possible mechanisms of the effect of psychotropic agents on the course of arrhythmias are discussed.