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A V Demin

Publications and source records attributed to A V Demin.

15 recordsLinked to original sources
PubMed2006

[The results of quantitative cytological analysis of the structure of follicular thyroid tumors using computer and neural network technologies].

Artificial neural network is a complex system capable of gathering and synthesizing data and capable of learning using particular given parameters. This technology was applied to studying cytological diagnostics of thyroid diseases to differentiate between follicular cancer and follicular adenoma. A complex of quantitative cytological characteristics was used to describe cytological preparations by examples of known cytological diagnosis to train the neural network. Among offered cytological examples, 96% were recognized correctly during testing.

Adenocarcinoma, Follicular↗
PubMed2003

[Roentgenosurgery for aortic coarctation and open arterial duct with intravascular ultrasonic examination].

Forty-five patients (32 with open arterial duct and 13 with aortic coarctation) were examined. Forty-nine intravascular ultrasonic examinations were performed, qualitative and quantitative analysis of 139 vascular segments was carried out. Despite the fact that mean morphometric indices of open arterial duct and aorta in angiography and intravascular ultrasonic examination had no significant difference, real confidence of the o data was seen only in 13.3% cases for open arterial duct an in 16.7% cases--for aortic coarctation. In 37.5 and 50% patients, respectively, difference in the dimensions was so significant that dictated choice of instruments with difference size. Roentgenoendovascular surgeries were performed in 23 patients with open arterial duct and in 12--with aortic coarctation. Choice of instruments parameters based on data of intravascular ultrasonic examination provided safer and more efficient procedures.

Adolescent↗
PubMed2002

Antibody proteases: induction of catalytic response.

Most of the data accumulated throughout the years on investigation of catalytic antibodies indicate that their production increases on the background of autoimmune abnormalities. The different approaches to induction of catalytic response toward recombinant gp120 HIV-1 surface protein in mice with various autoimmune pathologies are described. The peptidylphosphonate conjugate containing structural part of gp120 molecule is used for reactive immunization of NZB/NZW F1, MRL, and SJL mice. The specific modification of heavy and light chains of mouse autoantibodies with Val-Ala-Glu-Glu-Glu-Val-PO(OPh)2 reactive peptide was demonstrated. Increased proteolytic activity of polyclonal antibodies in SJL mice encouraged us to investigate the production of antigen-specific catalytic antibodies on the background of induced experimental autoimmune encephalomyelitis (EAE). The immunization of autoimmune-prone mice with the engineered fusions containing the fragments of gp120 and encephalitogenic epitope of myelin basic protein (MBP(89-104)) was made. The proteolytic activity of polyclonal antibodies isolated from the sera of autoimmune mice immunized by the described antigen was shown. Specific immune response of SJL mice to these antigens was characterized. Polyclonal antibodies purified from sera of the immunized animals revealed proteolytic activity. The antiidiotypic approach to raise the specific proteolytic antibody as an "internal image" of protease is described. The "second order" monoclonal antibodies toward subtilisin Carlsberg revealed pronounced proteolytic activity.

Animals↗
PubMed2001

[Rheolytic thrombectomy using the "Angiojet" complex in treating arterial thrombosis].

Results of roentgenendovascular treatment of arterial thrombosis by rheolytic thrombectomy with "Angiojet" are presented. 18 patients (1 woman, 17 men) underwent 19 rheolytic thrombectomies from peripheral arteries. Mean age of patients was 53.3 +/- 3.0 years, time of thrombosis--from 20-30 min to 60 days (mean 121 +/- 17 hours). Thrombectomy was performed from superficial femoral, popliteal or tibial arteries, or from all these vessels simultaneously. In one case thrombus was removed from femoro-popliteal graft. Rheolytic thrombectomy was combined with balloon angioplasty of hemodynamicaly important stenosis, 5 patients underwent implantation of 9 stents. Good and satisfactory results were achieved in 77.8% patients; thrombectomy as the stage of operation was ineffective in one case only. Rheolytic thrombectomy from coronary arteries was performed 3 times, with complete effect in 1 and with partial--also in 1 patient.

Angioplasty, Balloon↗
PubMed2000

Enzyme mimicry by the antiidiotypic antibody approach.

The concept of "internal image" of antiidiotypic antibodies has provided the basis for eliciting catalytic antibodies. A monoclonal IgM 9A8 that was obtained as an antiidiotype to AE-2 mAb, a known inhibitor of acetylcholinesterase, displayed esterolytic activity. Study of recombinant Fab fragments and separate light and heavy chains of 9A8 confirmed that the antibody variable domain encodes the catalytic function, whereas neither part of the primary sequence of the Fab exhibited homology with the enzyme. The specific modification of the 9A8 variable domain by an active site-directed covalent inhibitor revealed the presence of an active site Ser residue. A three-dimensional modeling suggests the existence of a functional catalytic dyad Ser-His. Comparison of active sites of 9A8 and 17E8 esterolytic abzyme raised against transition-state analog revealed structural similarity although both antibodies were elicited by two different approaches.

Amino Acid Sequence↗
PubMed1999

[Extracranial lymphatic pathways during the compensation of cerebral hemorrhages].

A process of brain haemorrhages compensation, manifested by migration of free erythrocytes from centres of haemorrhages into the cerebrum into the cervical lymph nodes was studied on 40 experimental and 37 sectional observations. Typical zones of forming of erythrocytes aggregations in nodes were revealed, dynamics of compensation process was shown. Experimental data were confirmed and groups of lymph nodes, participating in compensations of brain haemorrhages were shown on the sectional material.

Adaptation, Physiological↗
PubMed1999

[Thermal skin reaction to food intake and its changes in certain forms of obesity].

The authors review data on recently discovered temperature response of deep skin layers to the meal. The reaction is of a reflex nature and is one of the mechanisms regulating heat exchange in the body. In healthy people this reaction is weak. In alimentary obesity, it becomes much stronger, probably due to impaired heat exchange because of accumulated fat. In obesity related to diencephalic syndrome skin reaction is similar to control. In this obesity, pituitory seems to lose ability to regulate circulation in the blood. The above reaction can be used as a test differentiating the two forms of obesity.

Body Temperature↗
PubMed1998

[Design of constructions for the expression of proteolytic antibody light chain].

A new system for the expression of a catalytic light chain antibody to the vasoactive intestinal peptide is described. The system made possible the isolation the large amounts of a homogeneous protein without any additional peptide domains. The preparation obtained can be used in further experiments on light chain crystallization and in X-ray-structural analysis of its catalytic center.

Antibody Formation↗
PubMedDate not supplied

[A charge-deficient analogue of spermine with chelating properties].

1,12-Diamino-3,6,9-triazadodecane, a new isosteric and charge-deficient analogue of spermine, is synthesized. Unlike spermine, the new analogue is an excellent chelator of Cu2+ ions. Possible applications of this compound for studying enzymes of polyamine metabolism and cellular functions of spermine are discussed. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2005, vol. 31, no. 3; see also http://www.maik.ru.

Chelating Agents↗
PubMedDate not supplied

[A structure-activity study of a catalytic antiidiotypic antibody to the human erythrocyte acetylcholinesterase].

The catalytic monoclonal antibody 9A8 (MA 9A8), antiidiotypic to the antibody AE-2 (MA AE2) produced to the active site of acetyl cholinesterase from human erythrocytes, was subjected to a structure-function study. The specific binding of MA 9A8 to MA AE2 (K 2.26 x 10(9) M-1) was shown by the method of surface plasmon resonance, and the functional activity of MA 9A8 was demonstrated. Unlike acetyl cholinesterase, this antibody specifically reacted with the irreversible phosphonate inhibitors of esterases. A peptide map of MA 9A8 was analyzed by MALDI mass spectrometry. The Ser99 residue of its heavy chain was shown to be within the active site of the catalytic antibody. A computer modeling of the MA 9A8 active site suggested the existence of a catalytic dyad formed by Ser99 and His35. A comparison of the tertiary structures of the MA 9A8 and the 17E8 monoclonal antibody, which also exhibited an esterase activity and was produced to the stable analogue of the reaction transition state, indicated a practically complete coincidence of the structures of their presumed active sites.

Acetylcholinesterase↗
PubMedDate not supplied

[Structural-functional study of recombinant forms of onconase].

A method for expression of an onconase gene leading to a soluble form of the protein was developed. The enzymatic and cytotoxic properties of the protein's recombinant forms were studied. Recombinant onconase with an additional N-terminal Met residue isolated in nondenaturing conditions did not substantially differ from the native enzyme in ribonucleolytic activity. The addition of a 33-mer peptide containing auxiliary elements for the simplification of isolation and detection of the recombinant protein did not affect the enzyme properties of onconase. The method proposed is useful for the onconase structure-function relation studies and enables construction of onconase-based fusion proteins for anticancer therapy.

Animals↗