PubMed Health⌕ Search

Biomedical subjects

A A Totolian

Publications and source records attributed to A A Totolian.

At least 19 recordsLinked to original sources
PubMed2006

[Optimization of a method for determination of complement activity from 50% hemolysis of sensibilized red blood cells].

The method for determination of compliment activity from 50% hemolysis of sensitized blood cells (CH5) was modified in accordance with the recommendations of the International Clinical Chemistry Association, which could reduce the consumption of reagents, enhance the accuracy and reproducibility of results. The activity of CH50 was calculated for each serum sample by regression analysis, by graphically reflecting the results and by assessing the quality of each performance. The sigma-deviation method was used to calculate the normal CH50 ranges (55-160 conventional units) whose values were in compliance with the international standards. A series of experiments were made to assess the reproducibility of results. To evaluate the diagnostic informative value, the authors analyzed serum samples from 119 persons: 49 apparently healthy individuals, 74 patients with allergic diseases that are generally unattended by hypocomplementemia (Group 1) and 76 with disease the risk of which is increased in the presence of complement system defect (Group 2). Group 1 patients were those who had bronchial asthma or utricaria; Group 2 patients were those who had systemic lupus erythematosus, scleroderma, rheumatoid arthritis, chronic glomerulonephritis, acute glomerulonephritis, chronic furunculosis, chronic tonsillitis, or necrotic vasculitis. In Group 1, the value of CH50 was similar to that in the group of donors (108.0 +/- 3.1 and 105.1 +/- 3.8, respectively; p = 0.565), but it significantly differed from its mean value (91.6 +/- 5.1) in Group 2 (p = 0.00724). The difference in CH50 was also significant in the group of donors and Group 2 (p = 0.0349).

Animals↗
PubMed2005

Myocardial tissue damage in rabbits injected with group A streptococci, types M1 and M22. Role of bacterial immunoglobulin G-binding surface proteins.

Acute rheumatic fever (ARF) and acute poststreptococcal glomerulonephritis (APSGN), two important sequelae of streptococcal throat or skin infections, according to current concepts may be elicited by autoimmune mechanisms due to molecular mimicry between group A streptococci (GAS) and human tissue. In the case of APSGN, however, our experimental data have indicated that GAS immunoglobulin-binding surface proteins (IgG BPs) might be of pathogenic significance by triggering anti-IgG production and immune complex formation leading to renal damage. Thus, rabbits injected with IgG-binding, as opposed to non-binding, GAS strains were found to develop renal deposition of IgG and complement factor C3 and inflammatory and degenerative glomerular changes resembling the picture seen in APSGN. In the present study, cardiac tissue material from rabbits injected with GAS was investigated. After 8 or more weeks of intravenous (i.v.) injections, minimal changes were seen in those animals receiving an IgG non-binding GAS strain, type T27, whereas those animals receiving either of two IgG-binding GAS strains, types M1 or M22, developed strong inflammatory and degenerative myocardial changes accompanied by deposition of IgG and C3. Furthermore, on injecting rabbits with defined mutants of a type M22 strain, the development of myocardial tissue damage proved to be dependent on the presence of streptococcal IgG-binding activity. Our results demonstrate that myocardial tissue changes may be induced in the rabbit by i.v. injection of whole heat-killed GAS of at least two M serotypes. Conceivably, induction of immune complexes by bacterial IgG BPs may lead to myocardial deposition of IgG, in turn triggering a series of events, involving the complement system and proinflammatory cytokines, with resulting tissue damage. Though many virulence factors may be involved in the development of ARF and APSGN, and a given GAS strain will never cause both, our results may suggest a new pathogenetic mechanism common to these two major non-suppurative complications.

Animals↗
PubMed2005

[Comparative characteristics of specific autoantibodies in rheumatoid arthritis].

AIM: To assess diagnostic informative value of specific autoantibodies (AAB)--antikeratin antibodies (AKA), antiperinuclear factor (APF) and antibodies to cyclic peptide containing citrullin (CCP) from the family of antifilaggrine autoantibodies (AFA)--in rheumatoid arthritis (RA). MATERIAL AND METHODS: A total of 121 patients with RA and 45 patients with seronegative spondylarthropathies. Rheumatoid factor was detected with latex agglutination. AKA and APF were estimated with indirect immunofluorescence the substrate of which was series frozen sections of rat esophagus in the middle third of 4 mcm and cells of the epithelium of the internal surface of healthy donor's cheek. For detection of antibodies to cyclic peptide, the test DIASTAT Anti-CCP ELISA (Axis Shield, Great Britain) was made. RESULTS: The RF was detected in 67.8% patients with RA; AKA, APF and antibodies to CCP--in 43.6, 52.9 and 68.0% patients, respectively. AKA were most specific for RA (100%) while the RF was least specific among the AAB studied (87%). Simultaneous use of RF and AFA allows AAB detection in 84% RA patients at early stages of the disease. AFA were detected in patients with high clinico-laboratory activity of the process, high indices of functional joint insufficiency. 95% of all cases of destructive arthritis were detected in patients with RF, AKA, APF and antibodies to CCP. CONCLUSION: For RA patients it is necessary to determine both RF and AFA. Detection of AFA allows early diagnosis of RA as well as to single out patients with more aggressive course of the disease and unfavourable prognosis.

Adult↗
PubMed2004

Induction of myocarditis in rabbits injected with group A streptococci.

BACKGROUND & OBJECTIVES: We have earlier proposed that group A streptococcal (GAS) immunoglobulin binding surface proteins (IgGBPs) might trigger anti-IgG production and immune complex formation leading to glomerulonephritis. In the present study, cardiac tissue material from rabbits injected with heat-killed GAS was investigated. METHODS: Rabbits were injected intravenously with 10(9) colony forming units of streptococci three times weekly for 8 wk. Cardiac tissue samples were obtained at different times and deposition of IgG, C3, TNF-alpha and IL-6 was studied. RESULTS: After 8 or more weeks of intravenous (iv) injections, minimal changes were seen in animals receiving an IgG non-binding GAS strain, type T27, whereas in those animals receiving either of two IgG binding GAS strains, types M1 or M22, strong inflammatory and degenerative myocardial changes accompanied by deposition of IgG and C3 were noted. Furthermore, on injecting rabbits with defined mutants of a type M22 strain, the development of myocardial tissue damage proved to be dependent on the presence streptococcal IgGBPs. INTERPRETATION & CONCLUSION: The present data supported a role of streptococcal IgGBPs in the induction of myocardial tissue injury by GAS.

Animals↗
PubMed2003

[Current understanding of the pathogenesis of infectious diseases].

New experimental data in such research fields as molecular biology, biochemistry, genomics and others as well as the changes occurring in the medical-and-epidemiological situation in respect to a number of infectious diseases dictate the necessity to systemize and to revise the appropriate knowledge for the purpose of ensuring a more profound understanding of the processes providing a foundation for the relations within the system of "host--parasite". The article deals with modern aspects of investigating the pathogenesis of infectious diseases, i.e. issues of the genetic and of structural-and-functional organization as well as of regulation of the pathogenetic potential of microorganisms; and mechanism of antimicrobial protection of microorganisms including from the standpoint of evolutionary biology.

Communicable Diseases↗
PubMed2002

Quantitative investigation of the affinity properties of different recombinant forms of protein G by means of high-performance monolithic chromatography.

The recombinantly produced different forms of protein G, namely monofunctional immunoglobulin G (IgG) binding, monofunctional serum albumin (SA) binding and bifunctional IgG/SA binding proteins G, are compared with respect to their specific affinities to blood IgG and SA. The affinity mode of the recently developed high-performance monolithic disk chromatography has been used for fast quantitative investigations. Using single affinity disks as well as two discs stacked into one separation unit, one order of magnitude in adsorption capacities for IgG and SA were found both for monofunctional and bifunctional protein G forms used as specific affinity ligands. However, despite the adsorption difference observed, the measured dissociation constants of the affinity complexes seemed to be very close. The analytical procedure developed can be realized within a couple of minutes. Up-scaling of the developed technology was carried out using another type of monolithic materials, i.e. CIM affinity tubes.

Adsorption↗