PubMed Health⌕ Search

Biomedical subjects

Iu P Vartanian

Publications and source records attributed to Iu P Vartanian.

16 recordsLinked to original sources
PubMed1990

[The sorption of a protein-polysaccharide complex isolated from Neisseria meningitidis serogroup B on aluminum hydroxide gels and the immunological activity of the sorbed preparations].

The protein-polysaccharide complex, isolated from group B N. meningitidis, is a variant of vaccine for the prophylaxis of group B N. meningitidis infection. In this investigation the influence of the complex of the physical properties of aluminium hydroxide gels, the amount of gel, pH and the duration of sorption on the process of sorption has been studied. Aluminium hydroxide has been shown to produce a stimulating effect on the response of mice to the polysaccharide and protein contained in the complex after immunization made in two injections. Gels with a smaller particle size have been found to possess greater adjuvant activity, as well as greater absorbing activity. The immunological activity of the complex, adsorbed ex tempore, has proved to be no different from that of the complex adsorbed in an hour.

Aluminum Hydroxide↗
PubMed1988

[The composition of immune sera against Neisseria meningitidis studied by high-performance liquid chromatography].

The comparative study of the composition of immune rabbit sera to N. meningitidis, as well as nonimmune sera, has been made by the methods of HPLC and radial immunodiffusion. The quantitative evaluation of the main serum proteins by the two methods has shown the coincidence of the results yielded by these methods. To study the total level of IgM and IgG in the sera under study, a simple and rapid HPLC technique is proposed. The study of the stability of sera during storage (at 4-6 degrees C) has revealed that immune sera show greater stability during storage under such conditions in comparison with sera obtained from nonimmune animals.

Animals↗
PubMed1988

[A field trial with the liquid multicomponent meningococcal vaccine ABC].

The morbidity rates of generalized forms of meningococcal infection in persons immunized with different doses of liquid meningococcal vaccine ABC were compared. The vaccine was introduced subcutaneously by means of a jet injector. Altogether 3,920 males aged 18 years and older were immunized. 1,966 vaccinees received this vaccine in a dose of 200 micrograms and 1,954 vaccinees, in a dose of 400 micrograms. Meningococcal multicomponent vaccine ABC used in these doses showed moderate reactogenicity and did not prevent the development of generalized forms of meningococcal infection.

Adult↗
PubMed1981

[Detection of enterotoxigenic Escherichia in patients with diarrhea of undetermined etiology using experimental models].

Feces from 249 adult patients hospitalized due to diarrhea of unknown etiology were investigated. In 65.5% of the patients enterotoxic E. coli (ETEC) producing thermostable enterotoxin were detected by the anal test in suckling mice. As demonstrated by the paw edema test in mice, 79% of such strains produced also thermolabile enterotoxin, the remaining strains belonged to the ETEC variants, known from the literature, producing only thermostable enterotoxin. The antigenic similarity of the thermolabile enterotoxin with cholerogen was confirmed by the phenomenon of paw edema neutralization in mice. Among the cultures isolated from the patients 2 ETEC variants, which could not be differentiated by the test in suckling mice and by the paw edema test in mice and paw edema neutralization, were detected by the intranasal infection of mice.

Animals↗
PubMed1980

[Neutralizing activity of antisera to E. coli enterotoxin and a toxoid type preparation].

Antisera obtained as a result of immunization of rabbits with concentrated E. coli enterotoxin, its active fraction or toxoid, had a pronounced toxin-neutralizing activity. At the same time the cytotoxic activity of antisera to the purified fraction was considerably higher than that of the antisera to the concentrated enterotoxin. Such antisera had also a neutralizing effect on thermolabile enterotoxin. The neutralizing activity of antisera to E. coli enterotoxin was clearly manifested in the paw edema test.

Animals↗
PubMed1980

[Possibility of obtaining the anaform of E. coli enterotoxin].

The nontoxic (on the model of raw edema in white mice) anaform of E. coli enterotoxin was obtained under the action of heat and formalin. In the process of detoxication the charge of the enterotoxin molecules was changed. The toxoid thus obtained preserved the antigenic activity of the initial preparation and, when used for the immunization of rabbits, stimulated the production of active antitoxic sera.

Animals↗
PubMed1978

[Edema of the paws of white mice--test for assessing the activity of E. coli enterotoxins].

The authors studied the paw edema test in mice for detection of the E. coli (strain P-99) enterotoxins activity. This test proved to be simple, sensitive and reproducible; it permitted to determine the activity of thermostable and thermolabile enterotoxins and endotoxin; the mentioned test was particularly useful in testing various preparations of enterotoxins obtained during their extraction and purification.

Animals↗
PubMed1978

[Dynamics of biologically active enterotoxin release by E. coli].

Accumulation of E. coli enterotoxin in the Finkelshtein's culture medium in growing the cells in a 30-litre reactor was studied. Accumulation of active highly molecular enterotoxin occurred in the course of a 6-hour cultivation of E. coli, strain P-99 (O141: K85ab; K88ab: H4) in the fluid medium under aeration. Oxygen utilization, synthesis and release into the nutrient medium of pyruvic acid, and protein accumulation were observed. The preparation obtained was stable to the lyophylic drying, contained thermolabile and thermostable toxins and marked edema of mouse limbs. The data obtained were of significance for the industrial production of active enterotoxin preparations.

Bacterial Proteins↗
PubMed1978

[Opsonizing activity of sera from animals immunized with pertussis vaccine].

Opsonizing activity of guinea pig blood serum containing mercaptoethanol-resistant pertussis antibodies was studied in vitro on a model of microorganism ingestion by the mononuclears of the guinea pig peritoneal exudate. There were revealed distinct differences in the serum activity depending on the phagocytosis object. The blood serum of hyperimmunized rabbits stimulated the ingestion of Bordetella pertussis by mononuclears of guinea pigs--normal and immunized with pertussis vaccine. The blood sera of hyperimmunized guinea pigs and of mice immunized with pertussis vaccine twice displayed opsonins to B. pertussis. The blood sera of animals immunized with pertussis vaccine inhibited the staphylococcus ingestion by the peritoneal exudate mononuclears of guinea pigs, both normal and those immunized with pertussis vaccine.

Animals↗
PubMed1976

[Isolation of the thermolabile E. coli enterotoxin and the study of its biological properties].

Enterotoxin was obtained from the culture of E. coli O15 by salt precipitation and gel-chromatography. The toxic activity of the preparation increased during the isolation and purification: 60-fold according to the results of the method of ligated rabbit intestinal segment and 66-100-fold according to the skin test. The "plateau" and the second fraction obtained as a result of gel-chromatography were inactive according to the results of the method of ligated intestinal segment, but possessed PF-activity in the skin test. Two suppositions are put forward: 1) possibly the factor of vascular permeability and the diarrheal factor were two different substances ((molecules), or 2) the skin test was more sensitive for determination of the toxicity than the method of the ligated segment of rabbit intestine.

Animals↗
PubMedDate not supplied

[The immunological activity of Neisseria meningitidis lipo-oligosaccharide incorporated into liposomes].

Immune response to lipooligosaccharide (LOS), isolated from group B N. meningitidis cell wall, was studied after its incorporation into liposomes. The adjuvant effect produced by liposomal LOS, more pronounced in comparison with that produced by native LOS, was observed after the injection of the preparation by different routes (intravenous, intraperitoneal and subcutaneous injections), but the highest level of response was achieved after the intravenous and intraperitoneal injections of the preparation. Experiments aimed at the study of the dynamics of plaque-forming cells and the level of antibodies after intraperitoneal immunization of CBA mice with LOS revealed that immune response to liposomal LOS was more intense and prolonged than that to the free antigen. Liposomal LOS induced genetically nonrestricted and T-independent immune response. This fact was confirmed in experiments on mice having different haplotypes, such as CBA (k), C57BL/6 (b), BALB/c (d) and in nude mice with congenital thymic aplasia. In addition, liposomal LOS induced mainly the accumulation of IgM and IgG and did not produce the effect of immunological memory.

Animals↗
PubMedDate not supplied

[An acellular pertussis vaccine based on the natural complex of antigens isolated from the supernatant of a synthetic culture medium].

A highly effective technology for obtaining a protective antigenic complex, including the main Bordetella pertussis protective antigens (pertussis toxin, filamentous hemagglutinin, agglutinogens, pertactin and adenylate cyclase) and isolated from the supernatant of B. pertussis cultivation medium, has been developed. A new method for the detoxication of antigenic complex which more available to preserve the protective property was suggested. Experimental batches of monovaccine and adsorbed DPT vaccine with the acellular pertussis component, possessing high protective activity and low histamine-sensitizing properties, have been obtained. The stability of protective properties both in liquid and lyophilized acellular pertussis preparations has been noted.

Animals↗